Danke has just tipped us off to this brand new Ultimate Marvel vs. Capcom 3 video by Team Brown Town. It showcases an interesting piece of tech discovered by Phantasy and Rylander and expanded upon by Xero. Essentially, a low hit-stun move is used to force the opponent to block as they come in. Then, a DHC is used to tag into an anti-air command grab. Either the opponent takes the original hit and eats a full combo, or blocks and gets hit by the grab, but either way they can easily be killed as long as you have the meter.
The first video explores the theory behind this tech while the second shows an entire team being beaten by guardbreaks and TAC infinites.
Source: Team Brown Town, tip from Danke