Dormammu (a), Sentinel (a), Akuma (b)
Akuma goes through all projectiles they might try to throw your way, and is your “get off me” assist. If it hits, you get a free combo into Chaotic Flame with Dormammu. It can also be used in combination with Flame Carpet to OTG and relaunch in the corner or OTG-> Forward+H ->Dark Hole -> Chaotic Flame for a bit of extra damage and ease of use over his normal OTG -> super combo.
Sentinel Missiles assist is perfect for Dorrmammu. That plus dark holes and flame carpet keeps them out very well, and once again, if any of them hits, it’s a free super. Missiles putting them in block stun (Akuma as well) makes for a perfect time to put down flame carpet, which shuts down pretty much the whole cast while it’s out. Also, they aren’t a tight block string, so you can teleport behind them between the second and third missiles and get an almost free mixup. If they start blocking it correctly, you can change the timing of the teleport, or start teleporting in front instead.
I usually play keep away until I kill a character, put down Flame Carpet in the corner while calling Sentinel to setup the unblockable on the next character, X Factor to kill them, then try to get a mixup on the third to win.