Morrigan jumps in and uses a single soul fist. Generally accepted as one of the most useful assists in the game. It aids out teammates who require projectile support to advance, and also stuns while keeping the opponent grounded, making it perfect for extending combos. The firing time is slightly less than Ryu's hadouken so it does need to be used a little earlier.
Morrigan performs her light shadow blade. This is one of the best V.counters in the game due to the fact that she is completely invincible during the startup.