Marvel vs Capcom 2/Cammy
Best assists include Sentinel (G), Tron Bonne (G), Cyclops (B), Psylocke (A).
Playing with Sentinel (G): Can do j. Cannon Drill (RH version) while calling Sentinel (G) to back you up. Also can do call Sentinel (G), Cannon spike (either version). Sentinel Drones will often protect you (unless the drones are interrupted or hit the opponent's assist).
Crossup on incoming characters (in the corner only): Call Sentinel (G) (also works with Strider (B)), Cannon Spike (RH version) that whiffs on purpose (must execute this before the opponent is in the screen to whiff). You will end up behind the opponent as they come in and the opponent often can't even see where the drones or Strider is located (cross-up practically occurs below the screen). Free c. short, c. forward, c. fierce, etc. after the drones or Strider assist hits.
With Tron Bonne, it's very useful to use j. short, j. forward in combination while calling Tron Bonne. Use with the occasional c. short, c. forward, c. fierce attempt (safe against many characters), can you can have a virtual lock down (very effective vs. Sentinel and large characters).