Despite the fact Agito's plans were to finally deal with the one person who could stand against him on possibly equal terms.
He failed.
Horribly. Sho really kicked his ass, despite not trying to kill him.
I honestly think, Sho having won the fight, allowed Agito to let some of the weight he had been carrying, simply slip away. Allowing himself to believe that Sho could possibly do what he couldn't. And when Sho spared him ( and possibly passing the Exceed information to him), Agito probably realized how far gone he truly was. Thinking Sho was an enemy, allowing Shizu to become Griselda etc... The graves, and his reaction to Shizu later in the chapter showed an Agito that possibly regrets some of his decisions, despite how far they have gotten him.
Sho basically offered Agito a truce, despite noting that he still has some issues with Agito that need to be worked out before they can become friends/allies again.
Will we see a changed Agito? And if we do, how much of a changed man will he be? We will just have to wait and see.