My memory may be hazy, but I had a theory pop into my head just now, as I finally reset my password that I had forgotten and am now back on the forum! Happy New Year everyone! Still patiently waiting for the next chapter, I see! Me too. Anyway, here's my off the top of my head theory:
What if Alky activated Guyver 0's unit after using the Remover on the host, and that's what really scared the Creators away? Would explain why Apollyon wants the Remover from Guyot, no? I think Imakarum/Murakami is Apollyon, as much as I'd love for it to be an Advent, and I do think he could be their agent, in some fashion, as some stated above by others in this thread. It could also explain why Alky needs to rest for prolonged periods of time, because being a Guyver Zoalord was said to be unstable and too dangerous, if my memory is correct. Power overload. I think there's a possibility we weren't told the full story about the moon the Advents hurled at Earth. I could easily see Alky not being strong enough to stop it, and activating the Guyver unit as a last ditch attempt. Alky could be in need of all of his Zoacrystals back to control it, perhaps? If Apollyon is indeed Imakarum, perhaps he's being controlled telepathically, or his split personality is kicking up, and he was originally an Advent agent before Chronos got their claws on him. So many possibilities. It definitely *feels* like the Creators are going to make a reappearance going by the art in some of those panels posted above. Murakami started off as a "reporter", right? Then we found out he was a proto-Zoalord. Two personalities. Then Murakami became Imakarum. Two personalities. It could be a trend if we're to assume Imakarum is Apollyon?
This is all wild speculation, of course. There's always the possibility that this is just a brand new character being introduced, but all the connections are too coincidental.
Also, I can't remember whether or not it was revealed that Guyver 0's unit ended up being someone else's, so someone please inform me about that