So I decided to try beating Vanitas' Sentiment for the first time today. As the battle began, I thought, "Only
one health bar? That's not very ha-OMG WHAT IS HAPPENING DID HE JUST KILL ME IN TWO SECONDS??? WHAAAAAAAT??" I tried again, and again, and again, but he still pwns me every time. Curse you, Vanitas Sentiment! CURSE YOU!!!!!
I don't know where my usual welcome went to.
O_O Maybe Vanitas took it!!!!
SO, while I could ramble about a Vani-including crossover idea (Puella Magi Madoka Magica + KH; Roxas contracts with Kyubey, using his wish to protect those he loves, things go horribly wrong, etc...) BUT I think you'll find this more interesting.
Awww, I feel bad that I can't discuss that more with you, but my knowledge of anime and manga is extremely limited, so I wouldn't understand what you were talking about. At least I can say that I think Vani's a fun character for fanfiction purposes because he's so unlike any other character in KH, being a creature of pure darkness, that the story possibilities are endless.
What on earth was Vani's motivation the whole time?
Being pure darkness, "for the evulz" is a distinct possibility, but he seemed really eager to reunite with Ventus. Do you think Vanitas might've felt like he belonged with Ventus, and wanted to go back? He wanted the X-blade, and he wanted to be powerful and in control (that's kind of obvious, I think), but I think he wanted his heart to be whole again, too; he wanted it deep, deep down inside, methinks.
That's a really interesting idea. He showed a lot of disdain for Ven though, so if your theory is correct, then I think he was more attracted to the idea of being whole and having complete control over Ven than anything else.
When I played BBS, my impression was, essentially, "for the evulz." He's a being of pure darkness, and he seemed to REALLY like the idea of starting another Keyblade War. I think he just wanted to start a chaotic apocalypse where darkness would reign, and he didn't particularly care if he achieved it through MX's plans or his own, as we saw with the way he almost killed Ven and considered using Aqua instead. That's why I don't really buy into the accusation that he was just MX's lackey. I think MX just showed him a goal that he supported for his own reasons, and offered the most likely way of getting that goal accomplished.