Shang/Ferra
To compliment the B223 low:
B22~K, 2(Ferra overhead), 4~DF1(old form), 4~DF1, F4~DF1, B1~DB3 (401 damage)
Or the Ferra Low
B22~K, 3(Ferra low), 4~DF1, 4~DF1, F4~DF1, B1~DB3 (401 damage)
BNB, kinda tight though:
F4121~K, 3(Ferra Low), 4~DF1, 4~DF1, F4~DF1, B1~DB3(422 damage, 412 off F412)
You can combo from Ferra low slide full screen, just run up and do old F3 or F4 into ground skull loop, get like 330 damage pretty easily. Same thing off overhead from range, using old F3. Might have to settle for less damage of the real max range.
Ferra Yoyo toss is +15 or so on block. Testing against Li Mei, this was a frame trap into EX ground skull from full screen. Couldn't jump out, dash out, etc.
If you do Shang's normal BNB combo, you'll get like 30% of a super meter bar. If you hit confirm into it and summon Ferra "Lackey Variation", she'll cheer you on and you'll get like 50% of a bar. For a character like Shang with longer combos, it should be easy to take advantage of the extra meter gain. Also goes well with zoning.
You can do Old Man Air Skull right in their face and then go into Ferra Jump Punch and get a full combo, while being safe on block, no gap. Though they can flawless block the NJP to make it unsafe.
If you are godlike and do instant air young skull, you can cancel it into Torr stance jump punch for a full combo. Or just simply do a late fireball after a jump for the same result.
BF1(Air), K, 1(Ferra Jump Punch), 4~DF1(form change), 4~DF1, F4~DF1, B1~DB3 (381)
In general, it seems like Air Torr stance can be a nice tool with Shang because of his air specials that allow him to change his jump arc and whatnot.