[quote=CreedTheChimera]
"Sure, I could do that." Mavis says, before doing as asked, delving into Ventus' mind.
[/quote]

When Mavis dives into Ventus' mind, she is now standing on a circular glass platform. Vanitas is there to greet her, in his usual attire and his mask on. "......Mavis...what do you want? You have no business being here. This body is mine..." He says. This gives Mavis the impression that this is a past version of Vanitas. Ergo, he's much more harsh and cold-hearted.