To combo the Carb Smasher in the corner, some characters you have to do a half circle backwards motion, others you have you have snap the coil off and do a d-f motion. It can work every single time on every character. There is no way to combo it on any with simple attacks
Examples:
Omega in corner against Ryu, jump back, HP, land, LP, LP, MP, sj, LP, LK, MP, LP, MP, HP coil (with drain), throw them into the corner by tapping back, then quickly do F-D-B PPP without hesitating, and he’ll get it, cause I just got it 8 times in a row. Since they are already on the other side of Omega when you do the motion for the super, it’s almost like the same concept as an anti cross up tracking Dragon Punch. Some characters however, you can just do a coil throw, then D-F PPP right after it and it’ll get them, I just find it easier and more accurate to do the opposite motion like you’re rolling off the coil throw.
The reason you’re getting less hits on the MK in the air combo is because the coil grab can’t combo off the MK as far as I remember since the MK has a different reaction than the MP, so that would break it but almost appear as if it combos since I’ve gotten people with it online at least by accident, but as long as the CS hits of the coil throw, it combos, it can’t not combo, and on some characters like Cyclops, you will actually go through their feet.
Omega comboing Carb Smasher
As far as OTGing the OD, it’s just not practical, the only time you should really use the OD is if it’s a last move counter something of the match since anytime you can get a free OD, you can get a free near 50% combo with energy recovery, however I don’t always stick to that philosophy either, but it’s a good tip.
In the corner if you don’t have any super, same set up, throw them in, and immediately do a HK to flying state them, then otg, DLK, DMK, D+HP, in your combo, stick a MP in instead of the LK, and do a MP coil, throw them down the drain so to speak.
One other little combo I like doing is jump in, LP, MP, land LP, MP, sj, LP, MP, LP, MP, that’s 8 hits of LP MP, then coil. 
It’s also good to throw out tiger kneed CSes occasionally cause they catch people mid attack a lot with it’s major priority, also after that you can otg in the corner with a D+HK for an extra hit. Also if you get a tiger kneed coil out of the corner, throw into the corner without draining, and then launch them on their way down since Omega will land on his feet with enough time, sj, and air combo to coil, then throw them back into the corner and they will bounce off the wall to the other side of you, sets up disorientation and you can usually land quickl, D+LK, MP, sj, air combo, carb smasher and they are dead. Remember to throw out Omega Strikes and call them back from full screen when possible cause it’s really fast, the upward one is good against cross up attempts, and sometimes the diagonal one is good as Blackheart on his way up from a jump to throw piggies. Don’t forget about the sudden tiger kneed coils as they get peopel constantly cause it looks like a super jump at first, then snag. And more often, try to throw them to the ground with coils rather than in the air, unless you know they like to throw out air attack counters a lot, which I find some people do senselessly, and they wind up getting caught by stray coils. If you throw to the ground, you have a better chance to high low mix up, if they are ducking and blocking, air combo on the way down with LP, LK, since you are probably going to be in super jump, it’s faster hits, they sometimes try to counter before you land, but get snuffed, and if they block high, stick in the D+LK, MP to air combo.
Oh crap I forgot, Omega Red’s air dash stops on a dime, and as long as you do coils (and try to instantly cancel them), you can air dash again and again after each one a million times before hitting the ground. :tup:
Also go here, lots of my Omega in these matches, I’m Sin, you will see me combo the carb smasher in “sinvblazed3.wmv” about 30 seconds in.
Dark Addictz MvSF Match Vids
As far as MvC2, I have never been able to combo the Carb Smasher in that and I don’t know why, I’d imagine you still can.
Matt