vs. Faust, 6P, IAD j.H, undertow vs. his scalpel stab, 5K, mappa when he throws an item.
BBU beats out most of fausts ground moves. Definitely goes through the scalpel pull, 5S, 5H, pogo, etc etc.
If you're close enough for BBU to hit and faust is in pogo, it's pretty much a free hit.
Lots of stuff for getting in on faust.