Ragey found these unused graphics, which were originally from Marvel Super Heroes. That "GEM VICTORY!" text is also unused in MSH.
Whilst this text goes unused, it was presumably an early wording for the assist characters, which go by the name "Special Partner" in the actual game.
Unused assist character! His name is Tomichin, and he is a caricature of one of the game's designers. This caricature previously appeared on one of Marvel Super Heroes Vs. Street Fighter's Secret File pages. Thanks to Ragey for finding Tomichin's correct palette.
His first attack is this quick punch, although perhaps he was meant to throw out a projectile?
He also has a second attack, where his nose transforms into a fist, and extends to hit the opponent!
Finally, he has some sprites for being knocked down. In addition to these sprites, Tomichin also has an unused announce name call out, and possibly a couple of unused voice clips (see below).
To my knowledge there is no random select option in the game, so this is unused. It was possible this was used in the location test versions before all the characters were in the game, though.
This kid would have been in the bathtub stage, but he goes unused. I couldn't find any legs for him.
Sakura has an unused animation where her towel starts to fall off, she notices, gets flustered and then quickly fixes it. The final game just has her constantly doing her fist pump animation.
Kei seems to have some cut frames related to the unused Sakura animation, where she'd get shocked at her friend's wardrobe malfunction.
Unused music & voices
Unused track
This very short track can be heard in the sound test (0597).
Announcer: "Thank you for playing."
Announcer: "Coming Soon"
The above two clips were most likely used during the game's location test.
Announcer: "Tomichin"
Tomichin is an unused assist character, see above for more details.
Onslaught: "You shall be the first to fall"
Unknown: "Daijoubu ka?" (Are you alright?)
Unknown: "Ganbaru!" (Do your best!)
The above two clips were possibly meant for Tomichin, but I don't know for sure.
Venom: "Waste the creep"
Venom: "We meet at last"