My reasons why Anima would win:
Anima could easily kill Valefor with like 1-2 Pain attacks

A couple Blizzara spells and Anima could extinguish Ifrit

Ixion couldn't stand a chance against Anima.Her sheer awesomeness would get that sissy unicorn running.

Shiva...Now Shiva has 17% chance of killing Anima because of her high agility,high coolness stat(not as high as Anima's) and magic defense but Anima could destroy her with a few Firaga spells or Oblivion

Bahamut is a tough guy but is painfully slow and she could get her Oblivion ready way before his Mega Flare

Magus Sisters...They have a 3.00682% chance of killing Anima 'cause they could cheat and gang up on Anima.With Sandy's physical attacks,Mindy's black magic and Cindy healing.But Anima would get 'em.Her fierceness alone would scare off Mindy

and Yojimbo...

Anima could so easily whoop Yojimbo's @$$!!!one really good oblivion and he's gone and Yojimbo has like a 1/2,000,000 chance of doing Zanmato!

in conclusion...Anima would win...no matter what...