Kingdom Hearts II My theory

Ok, so these knights are supposed to be new characters, yet they can be "related" to existing characters. What if the soldiers are the people that the organizations members were made from. The organization members had to be created at some point when strong people became heartless. Maybe these soldiers are some of those people. The old guy could be trying to get them to turn into heartless so that he could have their nobody join the organization that he is creating. So the knight could look like Organization members and still be new characters.

When the E.S.'s eyes changed colors, that could be him becoming consumed by the Darkness. This would also explain why Mickey looked angry. He is probably trying to stop the old man from creating these nobodies.

This would also mean that these events are taking place in the past, which could explain why Mickey had the Star Seeker keyblade in particular. The Star Seeker could give you the ability to travel through time.