Ok so I'm gonna talk about the ninja's of mortal kombat, We'll start with the guys as they came first, then the girls and finally the cyborgs.
So as you can see, when MK started out they found a very good way to pad out the roaster with each game with minimal effort. Just recolour their ninja model and throw in some new moves. This is pretty much how all of these guys started out. Here we'll look at how they have changed over the years. I'll also only be touching or the core games for the most part.
So were to start? Well it can only be one of two characters Sub-Zero and Scorpion, being that they were in the original game. But who to pick first? While some will say Scorpion is the more popular of the two, I find Sub-Zero is a better starting point since while the two are rivals through the wholes series Scorpion's backstory is tied directly to Sub-Zero, while Sub-Zero's isn't tied to Scorpion.
It's pretty easy to forget how different the story of the original MK was to later entries, especially when pretty much everything else after it retconned the story. In MK1 the tournamant is not a battle to decide the fate of the world. Instead it was originally a tournamant held by the Shaolin Monks to see who the grand champion was, then an evil sorcerer came who was cursed by the gods to steal the souls of other to maintain his life. Tsang Sung became champion and kept entering in order kill more people until he was beaten by Kung Lao. He returned some years later with an outworlder named Goro who acted as his champion and allowed him to take control of the tournamant totally. Since then he's been using it to feed on the combatants. All of the fighters in this MK are human's bare Raiden, who incidentally is a bored god who was invited by Shang Tsung, and Goro. Going by the promotional comic, Sub-Zero's real name is simply "Unknown" although he I stated to be an assassin from the Lin Kuei. He's been hired to assassinate Shang Tsung. In both Scorpion's ending and the comic it is shown that sub-Zero did kill Scorpion in the passed, although there are some differences such as Scorpion's family still being alive. Not much else is stated however as the least amount of time is spent with these two and Sub-Zero is the most enigmatic of the whole caste. The most emotion he show's is shock at Scorpion being on the boat to the tournament.
In the first game Sub-Zero's outfit is pretty much one of a stereotypical ninja, although shoulders are a bit more puffed out and of course it's bright blue. That's kind of counterintuitive to his role as an assassin since the whole point is to sneak up and kill someone befor they even know your there. It's not exactly helpful in the stealth department either. That said he's a Lin Kuei not an typical ninja, so maybe his clan had a different code of conduct to most in their line of work. Combat wise he's only got two special attacks although they are two that would remain a core part of his skill set for the rest of the series, Freeze (a blast of cold that freezes his foes solid) and the Lin Kuei Slide (A low sliding kick). His fatality is the Spin Rip, possible the most iconic fatality in the original game and pretty much put the series right in the cross hires of Censorship crowd. This eventually lead to the creation of the Entertainment Software Rating Board (ESRB).
In his ending Sub-Zero killed Shang Tsung, earned a pretty penny and retired from his life as an assassin.
Mortal Kombat 2
In MK2 the backstory of the original game remains somewhat intact although it is revealed that Shang Tsung was actually serving the interests of a greater evil. Shao Kahn, Emperor of Outworld. It is here that the cannon ending of the first game is stated, Liu Kang was the victor and bested the sorcerer. Tsung went crawling back to his master and begged for a second chance, Kahn granted his request and restored Tsung to his youth. His plan is to now lure earths warriors into Outworld's tournamant to be killed by Shao Kahn himself. In MK2 it's stated that Sub-Zero was thought to have been killed in the last tournamant, yet he has apparently resurfaced to assassinate the outworld leader Shao Kahn. He's ending states that he is actually the younger brother of the original Sub-Zero, who learns of Scorpion's hatred of his elder yet cannot understand why his life was spared implying that Sub-Zero was bested by Scorpion during the story.
Design wise Sub-Zero has had some minor changes. The most notable being that his hood is now more skin tight and his mask has been mad into a solid guard piece rather then simple being cloth. His move set know has Ground Ice and the fatalities Ice Shatter and Ice Grenade.
Mortal Kombat 3
So after losing to Liu Kang, Shao Kahn decides to invade earth realm via another means. He has his Shadow Priests resurrect Queen Sindel on Earth, which allows him to cross over to reclama her since she is a citizen of his realm. By using this loop hole Outworld is able to invade Earth Realm and begin fusing the two. Sub-Zero appears to help fight against Outworld but a lot has happed since the last battle. The Lin Quie had begun "enhancing" their warriors with cybernetics (Later referd to as the Cyber Initiative) and Sub-Zero along with four other members were selected to undergo the process first. Given no choice to refuse, Sub-Zero abandoned his clan along with his friend Smoke. this was viewed as an unforgivable act by the Lin Quie, who send out their two cyberized warrior Sektor and Cyrax to apprehend the traitors. Smoke was captured by the pair and also cyberized. Now Sub-Zero must try to fight of three deadly assassins why trying to aid the other Earth Realm warriors in pushing back the invastion.
As you can see Sub-Zero's design is noticable changed from what it once was. In fact he's the first of all the MK ninja to begin to deviate from their simple pallet swap motif. His face is now completely unmasked, he's ditched his black undershirt, the blue piece on his upper body has been cut back to about half it's original width, his ice blue colouring is now much dark blue (and it would remain that way for the rest of the series) and he know sports a scare across his right eye. How he came by this scar is never stated and a lot of theories exists about it. The over all change was likely done for multiple reasons. First MK3 had no less then 6 ninja characters with a playable version of the original Sub-Zero, Rain and Chameleon being added in later versions. Something needed to be done to make him stand out from the horde. The other likely reason was due to his change in character, Sub-Zero has begun his path towards a more heroic way of life and given up his assassin ways. This change in attire better reflects this more heroic personality. MK3 also gave Sub-Zero, and most of the caste, a much bigger move pool to play with, with him now having Freeze, Ice Shower, Front Ice Shower, Behind Ice Shower, Ice Clone and Ground Slide.
Sub-Zero's ending him face all three of his cyborg assassins however he is able to reach his friend Smoke and the two team up to best their former Lin Quie breatharian. Together they defeat Shao Kahn and his forces befor disappearing into the shadows.
Mortal Kombat: Movie
This is the only part of the expanded series I'm gonna touch on but I have my reasons. The MK movie is were a lot of the elements found in MK3 would be retroactively fit into the story of the original MK. While only 2 characters from the later games would appear in person, Kitana and Shao Kahn, a lot of plot elements were used to better stream line the plot. Such as Outworld wanting to invade Earth Realm from the get go and the Mortal Kombat tournamant being in place to stop Shao Kahn from simply invading any realm he pleased. The elder gods made it so that only mortals from both realms may compete, preventing Shao Kahn from cheating to a digree, and Outworld must achieve victory 10 consecutive times befor they can invade. Also rather then all the earth warriors beating eachother bloody just to see who's best, Earth Realm's best face off against Outworld's. While not all the elements of the film's plot are treated as cannon down the road, a good chunk of it is.
I just want to point out that the how Mortal Kombat worked was very intreasting and seemingly a little nonsensical. While the tournamant has set matches, fighters could just meet up and fight on their own also. Normally it's one or the other. It reminds me of something from the Baki manga were it's stated a "champion must be ready to defend his title at all times" not just in a ring. I can only assume this is allowed so that the tournamant is intentionally somewhat chaotic, which makes it harder for any one side to try and manipulate events. That or the guy making the rules was either lazy or a dick. Also since you have at a god and a sorcerer watching over things, you can be shore at least both sides are keeping score when it counts.
Since were here Sub-Zero in the film is pretty much here to look cool, fight and little else. Here he's fighting for Outworld alongside his rival Scorpion, both of whom Shang Tsung has control of. As a result he has little to no personality. His over all design is somthing of a watered down fusion his MK 1 & 2 outfits but with a little les detail. The frosty face mask is pretty cool however. It's fair to say that the films CGI effects hand not aged well but Sub-Zero's cryomancy holds up a little better the most and the use of practical effects helps also.
Mortal Kombat 4
MK 4 is were a lot of people think the MK series started to loose it's steam. While a lot of it's core elements were still intact, the series was trying to find way to keep going and the directions it took were not always for the better. It started following other fighting game trends, like movies from 2-D to 3-D style fighting, having arena hazards etc but something was just missing. It didn't help that while a lot of their new characters created between the 4th and 8th game were mostly bland. That all said the series still easily come up with cool knew ideas and tell an intreasting story.
By this time Sub-Zero has disbanded his old clan and now seems to be without purpose at this time. In the wake of Shao Kahn's defeat however the Elder God Shinnok has risen to power once more and seeks to conquered all. Sub-Zero once again sides with Raiden to face Shinnok brining with him information on how to combat the dark elder god passed down to him from his older brother Bi-Han, but finds himself in conflict with Scorpion once more, the yellow ninja convinced that it was Kuai Liang was responsible for the death of his family.
Sub-zero's design is clearly an attempt to stay more faithful to his original design. Unfortunately I feel it doesn't overly works. While the basic premise is ok it feels to bland in places, also the cat-ear like pints on his hood and seemingly cloven feet just look weird. It's by far the character's weakest design for me. As the series went forward, it appears that the creators desperately tried to remove lazy symmetry of the ninja characters, with that in mind it's a little odd that Sub-Zero, who was the first to have his design altered would be changed back to his classic one in this game. MK4 did introduced alternate costumes for the characters and Sub-Zero's are a little better then his main, the first is a reworked version of his MK3 design combining it with his current one and the second had his arms and legs encased in ice, something that would become a reused in his future designs. It's in this game were we first learn both Sub-Zero's true names and alluded backstory between the brothers is hinting at events in the MK Mythologies: Sub-Zero game. The game had you play as the original Sub-Zero who was sent on a mission that tied to Shinnok and lead to the events of MK4. Power wise Sub-Zero is back to using only his core 3 moves once again however he can now us an Ice Staff in combat.
In his ending Sub-Zero is bested by Scorpion, who is about to slay him until Sub-Zero states he has no idea what the yellow ninja is talking about. It is then that the necromancer Quan Chi appears and in his arrogance tells Scorpion he had no intention of honouring their agreement, which prompts Scorpion to kill the necromancer and make peace with sub-Zero.
Mortal Kombat: Deadly Alliance
After the defeat of Shinnok, Sub-Zero would find himself in conflict with Sektor once again, this time is was for the soul of the newly reformed Lin Quie. Sub-Zero beat the cyborg, becoming Grand Master and took possession of the Dragon Medallion which increased his power. Sub-Zero vowed to reform his clan and moved them to a hidden temple in the arctic, where they could train and rebuild uninterrupted. During this time he gained a promising pupil, Frost, unfortunately her while skilled she was arrogant didn't agree with her masters ideals. Peace was not to last however as Quan Chi was able to escape the Scorpion, who had imprisoned and tortured him after Shinnok's defeat, and formed an alliance with Shang Tsung. This "Deadly Alliance" had slain Shao Kahn, then Liu Kang and were now working to resurrect the immortal army of the ancient Dragon King. Raiden requested Sub-Zero's aid once again and the grand master agreed to help, in part to help set a good example to his clan. He also took Frost with him, hoping the experience would help her develop into a better warrior
Sub-Zero's design in this game is a very radical departure from what came befor. He's older, his scare is blue and while his outfit is akin to his MK3 design, it's far more detailed and ornate. He's for-arms are permanently encased in ice. The over all look fits his new role as a Grand Master and while he looks older, he also looks wiser and more powerful. It's also a far cry from his days as a simple assassin.
In his end Sub-Zero returns from defeating the Deadly Alliance returned to the Lin Quie a hero and ready to defend earth realm from any threat.
Mortal Kombat: Deception
In the canonical events of Deadly Alliance, Frost betrayed Sub-Zero and attempted to claim the Dragon Medallion for herself. She was unable to control it's power however and her cryonic power went out of control, seemingly killing here. The grief stricken Sub-Zero, who placed all the blame on himself, took Frost and searched for a place to lay her to rest. He eventually found an Outworld ruin that belong to a clan of cryomancers, of which Sub-Zero become convinced he and Frost were related. He laid her to rest in the ruins crypt and dawned armour he found there, embracing his new heritage. He then tried to reconvene with Raiden and the others, only to learn the terrible truth. Raiden had been forced to face Quan Chi and Shang Tsung alone, worse in the middle of the battle Onaga the Dragon King (Former Ruler of Outworld and a being even Shoa Kahn had called master) had been resurrected. Despite their combined power and a last ditch suicide attack from Raiden, Onaga still lived and was regaining his power.
Sub-Zero's design here is a fusion of his classic design with his more ornate current one. A fusion of ninja and warrior. I feel this actually reflects his current state of mind very well, as he has had his faith in both himself and the future he dreamed of tested. He needs something to help keep him grounded in these dark times and finds it in this discovery of his heritage and possible slipping a little into his old ways also.
Sub-Zero doesn't play a part in the final battle against the Dragon King. Canonically he spends his time traveling around Outworld and NetherRealm battling the forces of evil.
Mortal Kombat: Armaggedon
Long ago the elder god Argus foresaw the destruction of all realms. As more and more powerful warriors appeared their ever intensifying combat would eventually destroy the realms. To try and prevent this he tried to create a fail safe. He created the Pyramid of Argus and tasked the elemental Blaze to watch over the realms. When the time was right Blaze would ascend to the top of the pyramid and draw all the warriors to him with the promise of power. Befor this he would send out a sign that Argus's son's Taven and Dagon, who were in hibernation, should be awakened and begin their quest to stop armagendon. Should either of them complete their trials and defeat Blaze, all the warriors would be stripped of their power or killed depending on the victor. Should they fail, then hopefully a warrior would arise to bring some form of balance in some way. Sub-Zero met and battled Taven, testing him to see if he were worthy of the relic in the Lin Quie temple. He would later be drawn into the final battle siding with the forces of light.
By the time this game out MK seemed like it was on it's last legs and this was truly the end. The game had a lot of problems but they really tried to give the series a good send off if this was it. Sub-Zero's design is a fusion of his classic design with elements that he would gain later. It doesn't appear to have any strong bearing on his character or maybe it reflects him turning to his old ways with armagendon on the horizon. More then likely this was done simple as fan service.
If Sub-Zero had been victor of the final battle, Sub-Zero would have become an ice deity... but one without the approval of the other gods, who would seek to destroy him.
In the canonical end, while Armageddon was prevented the actual outcome was not much better. The resurrected Shao Khan proved to be the mightiest warrior and absorbed all of Blaze's power.
Mortal Kombat 9
With Shao Kahn's ultimate victory at hand, Raiden attempted to cheat fate by sending his memories of all that had transpired to his passed self during the original Mortal Kombat, with the cryptic last words "He must win". Thus the Raiden of this new timeline must try to make sense of these vision to put reality on a better path. Despite Raiden's best efforts most of his efforts change little. Bi-Han is still murdered by Scorpion and Qui-Liang takes up his brothers mantel and sides with earth realm to take down Shao Kahn. He and his friend Smoke are also fleeing the cyber initiative. However in this timeline Qui-Liang seeks out his brothers killer to avenge his death, however befor he can kill Scorpion he is captured by the Lin Kuei. Sector and Cyrax offer allegiance to Shao Kahn for the right to apprehend Sub-Zero without interference.
MK9 was the first MK game to be made by NetherRealm studios after Midway had ended the series. Rather then just wipe everything away, they decided to reboot the timeline. In this game you play through the events of MK 1, 2 & 3. However here all of the changes to the series plot are made part of the games story mode, creating a more cohesive narrative with some new stuff thrown in to spice things up. Sub-Zero's design in this game is pretty similur to his Armageddon one. It's an updated version of his original designs, although here it makes more sense given that this is an updated retelling of the original story. Bi-Han's design is the more simplistic of the two, the over all design being a very plausible get up for an assassin. It's also noteworthy that the blue of his cloths is darker then his younger brother, better reflecting his darker soul. Kuai Liang's design is more ornate and brightly coloured, displaying his more heroic nature.
No unlike the original timeline it's Sub-Zero, not smoke, who is captured which leads to...
Unit LK-520! At first he is but a slave to the Lin Kuei but Smoke is eventually able to free him. He then acts as a spy against the Outworld forces until his cover is blown by Sektor. After defeating him Sub-Zero works to free prisoners from Shao Kahn's forces, taking on and besting Goro and Kintaro 2 on 1. After everyone is safe his next mission is to stop Quan chi from summoning a soulnado but this brings him into direct conflict with the Black Ninja, Noob Saibot! Fortunately he is able to best his dark counterpart and return to the other heroes triumphant... just in time for Queen Sindel to walking in and murder curbstomp them all! With most of earthrealms warriors killed, Raiden tries to make a last ditch alliance with Quan Chi, if he helps earthrealm he can have the souls of every slain warrior. Unfortunately Shao Kahn already made that deal and had made good on it, as Quan Chi summons the souls of the fallen heroes to attack the god. Raiden is eventually able to defeat Shao Kahn when we realises what "He must win" ment. While Shao Kahn is able to invade earthreal thanks to Sindel, he has no right to merge them and when he tries, the elder gods appear and destroy him. Victory is achieved but at a very heavy price.
I'm not going to say anymore about Cyborg Sub-Zero as he goes in the Cyborg Ninja Category.
In Sub-Zero's tower ending he and Scorpion learn the truth behind their loses and together they destroy the Lin Kuie. The two disappear into legend, only appearing to defeat evil. The Forces of Darkness cannot defeat this Deadly Alliance!
Mortal Kombat X
Sub-Zero become a warrior for the NetherRealm, fighting for Quan Chi and his master, the Elder God Shinnok. During this time he had been returned to his human form. Eventually Shinnok was beaten and Sub-Zero was one of the few warriors revived and freed from Quan Chi's control. In the years that followed he followed the path of his other self, rebuilding the Lin Kuei, becoming their Grand Master and even taking up Frost as his pupil. In time we would even finally make peace with Scorpion, showing him that yes the old Lin Kuei had a hand in his fate... but so did his old master Quan Chi. Five years later, Sub-Zero is met by Cassie Cage and her team under orders from Cassie's father Johnny. Not wanting to converse with them, he and his warriors engage them in battle. Defeating Cassie and her team, Sub-Zero reveals that the encounter is a test set up by him and Johnny, chastising Cassie's team's lack of unity while commenting that they have great potential.
Sub-Zero and the Lin Kuei are present for the resurrection of Shinnok, combining their might with the Special Forces and Shao Lin to fight off Outworld and NeatherRealm forces until Shinnok is defeated.
There's little I can say here about the designs. Sub-Zero is currently following the more heroic path he did in the alternate time-line and his designs reflect his character growth in the same way. The outstanding one is his revenant form which along with is more edgy design and plates of ice armour (hello MK Movie) but also a darker shade of blue... much like his brother!.
In his tower ending, Sub-Zero seeks greater power to help the Lin Kuei better defend earth realm, He travels to outworld and discovers a nest of Frost Dragon eggs, Using his power, he is able to hatch the young dragons and they accept him as their master. With the addition of dragon raiders to their forces, none dare threaten earthrealm!.