EDIT: 6c thing was directed at an earlier post. 5a is a better move as long as you use it intelligently.
I'll have to check on 6c, but I'm pretty sure that's a terrible idea. All Carl has to do is turn her on and right back off, you do 6c, and he uses 5c to get a nice CH combo that leads into loop>death.
Also, with my trick, Carl doesn't even need half Nirvana meter to loop Tager to death, so seriously, don't bother fighting Nirvana.
Carl approaching from the air is seldom going to happen unless you secure a life lead/they get impatient/cocky.
I say you should IB, superjump, and take the hit from it. After 2-3 hits from Rhapsody, you'll be free to tech out and hit Nirvana once or twice. Just don't get too close, because she hits slightly behind her sometimes. Watch out for Carl flying in with an airgrab when you do that, and you should be good to go.
Though he still might fly in and try to BS pressure until Nirvana's done, and then lead into a combo. Gotta stay awake.
If you're saying:
You - Gear - Carl
I dunno what all you can do to punish him. Magnetism ~might~ work, but I dunno if he gets pulled during it. My suggestion is to hit up training mode and try a bunch of stupid stuff. Just keep an eye out for Nirvana, since he can still command her while the super is going on.
Well, you won't punish his 5b, per se. It's a jcable, chainable, linkable normal. Buuuuuut
If Carl is going solo, you can watch out for two main things (assuming he doesn't have meter):
6b (the low swipe thingy) - IB this and you can punish him with a jab/something fast. I dunno what all tager can do. Watch out, though, because it's special cancellable, so he can do the ankle snare, super, whatever. If it hits, it's also JCable, and leads to a 50-50 that you don't want to deal with.
jcing>j.2c shenanigans - If you see him take to the air, you can choose to either block (if he's alone, he'll prolly go into another low>50/50 reset), or backdash>buster or whatever. While j2c can be made lagless via allecan, he has to actually connect with your hitbox to do it. If you backdash and he didn't anticipate it, then he's got 30 frames of landing lag that you can punish him for. Spark volt combos are go, if you have it.
As always, be really careful when he has super meter. He won't do damage, but any Carl worth their salt will combo into gear super to burn a LOT of time in order to make sure Nirvana comes back. If Nirvana comes back, chances are pretty high that you're dead if you aren't comboing him. Stay away from corners, because even without Nirvana, Carl has some stupid options vs Tager, esp when he has meter. j.2c allecan spam>50/50s until he has heat, and then force a block xx gear to make you block until Nirvana's back.
Oh, and with gear super in the corner, carl has a +18 frame advantage, so he can get back in while you're still blocking it and do a quick overhead>low or low>overhead. Poor Tager.
Well the thing with j.2c is that he can cancel it into allegretto to either give him 0 landing lag, or, if he's high enough, he can have allegretto actually come out (though there's really not much point to this outside of the corner). If he doesn't cancel it, you can do something like... 2c, I think? buuuuut he can also do
j.2c, j.b, j.c
And land with very little lag/at frame advantage, if he does it low enough.
Or he can jump cancel it. Or super cancel it. Or a lot of things.
I'd recommend learning to IB the j2c and backdash it. Then, when you're fighting bad Carls that don't allecan, you can IB the j.2c and get a free combo. When you're fighting good Carls, you're gonna have to guess on whether to IB>punish, backdash>punish, or just IB>keep blocking.
If he airdashes at you without Nirvana, you can rely on backdash a little more. If you see that robot show up once, get ready to block for a while, and watch out for resets once the pressure starts seriously taking Nirvana meter to do. Every time she does an attack without shutting off, it takes a little more health, until the punch takes 1/4 of her health and she dies. Most Carls will go for resets before this. You just have to know what to look out for, and play REALLY solid defense. Green grabs, unblockables (not very common without 100% meter), xups, really fast high/lows, gear super nirvana resets... you gotta be on point with your blocking, or else this match will never go your way vs good Carls.
Also, if a Carl does Gear Super while you're sandwiched, do NOT jump. I've been using this trap for a while now, and it gets good players and scrubs alike. Once I've turned her on and off again, you can bet I'll be spamming 8d to try and secure a loop. The only time I'd suggest jumping is at the end of the gear. Your goal is to get hit by the clap, get knocked into the last 2-3 hits of the gear, and fly away because the Carl really wasn't expecting it. Even then, this is a REALLY risky manuever.
Tager vs Carl is kinda like Carl vs Rachel. You want to keep blocking/playing conservatively until they get irritated and go in for their mix-ups. If your blocking isn't up to par, you will probably lose. If it is, though, you might be able to survive long enough for him to turn Nirvana off for a second in order to reset health scaling. As soon as you see that, keep an eye out for cape>quick solo Carl mixup, and try to backdash it and start the match rolling in your favour. Watch out for super cancels/rcs, or for him to do cape>jc>karacan airdash>pressure/loop if he senses the backdash, though, because if you've got Carl to the point where he had to turn off Nirvana during pressure, you can bet he'll be busting out his dirtiest tricks.
Hope that helps.