If it is anything like Melty Blood, it is the standard Dragon Punch, quarter-circle forward, and quarter circle back that is common to most fighters.

Melty Blood was just a mix of those where the attack varied depending on which strength of attack you pushed, A B or C.

Commands like Archer's phrases to bring out UBW are probably more unique and complicated, but Melty Blood's were fairly simple, most characters had the same input for all the super attacks.