I'd better actually get the first one before the second one comes out... it looks pretty good, and I like me some Tifa and Kain. Here's hoping for Edgar! Oh, and Galuf, Lenna, or Faris would be great too :D
I wish they'd make a Create-a-Character mode or a Customize feature on their costumes.
Oh and add special support moves from the characters respective world like Wakka throwing a blitzball at the opponent and Tidus following up with a Sphere Shot. Or 4-way fights.
There wont be any decent images of Tifa lockheart for Dissidia Duodecim yet but this video should suffice until the time does arrive. Sadly they are way too focused on lightning and the new paradigm shift aspect they are introducing to the game.