After further analysis, I have to say Tatsuya assist was heavily buffed by Rakurai.
According to a friend of mine who actually owns and plays the game on a regular basis, Tatsuya's counter assist has some limits. It can only stop one hit from a projectile, Rakurai's can negate ANY kind of projectile, regardless of how many times it hits (strangely enough, Tatsuya can't negate projectiles from Omegapsycho's MK chars.), and not only that. Tatsuya's counter can also negate ANY kind of throw (normal or special/super) and even can stop LA, other counters and even full screen moves.
My reaction... :/