I know how do unlock Christie's 3rd costume but i am working on the rest. Choose Time Attack, then tag, choose either Christie or Helela 1st. Do this and complete it in under 3 mins to get Christie's 3rd outfit which is really groovy.

i tried doing the tag battle thingy and it didn't work! what am i doing wrong??????????

I know this question is a bit dated, but i'll say anyway.

For zacks third costume, get 20+ wins in survival mode.

For ayanes thrid costume Get the silver Xbox item in Survival Mode

For Ein third costume Complete ''Time Attack Mode'' under 6 minutes with Ein.

For Kasumi's third costume Complete ''Exercise Mode'' in ''Sparring Mode'' with Kasumi.

For Zacks Forth costume Get the silver Xbox item in Survival Mode

For Jann lee's third costume Get the silver Xbox item in Survival Mode

There is a way to get Hayabusa's 3rd costume, though i'm not sure on what it is! i think its something to do with survival mode and points. I dont know how many points though.

Also on most characters, by pressin different buttons to select them, like X & Y instead of A, most of the characters costume will change colour. For Lei Fang hold the L trigger and press X on her red dress....to turn it black.

The suits apparently unavailable in the NTSC version without the download.

They were included in the PAL version as unlockables.

I'm pretty sure to get Hayates 3rd costume you have to get 2 000 000 points in survival mode as Hayate. (Haven't done it yet)