tutti frutti. This is assuming that the Unknown/Mysterious Figure has thorough abilities in controlling and traveling through time. Suppose that the Unknown from BBS had the ability to travel through time, and was able to bring those have have been defeated to the current point in time where Sora and Riku are in the midst of taking the MoM. If possible, that could be one reason that Vanitas returns, but at the same time he could also bring back other characters that have been defeated by Sora and Co. over the course of the series.

Aw lawrd we do not need like Sora and everyone else fighting over 9000 Xehanorts and who knows what else.

There's actually proof that he has powers of time, according to a new interview with Nomura. He is also related to Vanitas, as well as Eraqus and Xehanort.

 

Who knows if he has that power. That means that everyone that was fought before would come back. Since Nomura said there was no afterlife for any of the characters, he might mean that even the enemies will never die.

That would explain why the fight in BBS with him counts as canon... more or less.

 

However, why would he, if he is the

young Xehanort

(is this considered a spoiler?), bring Vanitas back? Does not seem like such an evil guy to me.

There's actually proof that he has powers of time, according to a new interview with Nomura. He is also related to Vanitas, as well as Eraqus and Xehanort.

 

Who knows if he has that power. That means that everyone that was fought before would come back. Since Nomura said there was no afterlife for any of the characters, he might mean that even the enemies will never die.

 

tutti frutti. In BBS if you use a couple of basic attacks, the Mysterious Figure will freeze time around him for a brief period and heal himself for a small amount of health. That is the only time I've noticed him having any control over time. But this was assuming that he had more control over time, kind of like how we saw more of what Xemnas and Terra could do in KH2 and BBS respectively. Though we can't really say what happens to characters when they are delivered the final blow, as what you mentioned from Nomura saying that there is no afterlife, but that was just a guess assuming that characters like Saix, Ansem SoD, etc. were brought back from the past to the present for whatever reason.