lol, that takes me back to Cadenza days... oh Ciel, how I hated you back then.
Well, you mentioned hiero so I'm assuming C. The thing to note is, there is a rock-paper-scissors to every fighting game, and you will need to take risks against players who gamble like that. Just remember to think about risk/reward and the right counter to the move he's using.
I don't see Ciels nowadays but I don't think 2C is a good move to mash, good pressure is the key here. Stagger, reverse beat and IAD. If I'm not mistaken 2CC isn't cancelable on whiff, right? Shouldnt be hard to let him hang himself on neutral. You have charged teleport to punish his projectiles if he abuses it.
Mashing loses to meaty, but if he is mashing on wakeup and you're letting him, I'll assume you're afraid of reversals. There are ways to beat reversals, one is reversing controls (which nanaya can do easily, but in her case it's worthless - 236C <> 214C, 22C) one is option select (won't work on EXs), which leaves you only with baiting.
22C and 236C lose to block, 214C loses to jump behind or shield->jump get air hit (recover towards her and then punish). You'll notice that all of those are meter dependant, so do what you can to deny her meter and if she is out of it go for oki without fear. The thing is, you can't do meaty and block at the same time, so you'll have to make sure that when he guesses wrong you're gonna hit him harder than he will you when he guesses right, which is not hard.
Then if he starts gambling shield or backdash on wakeup, you're gonna have to outsmart him with high/low oki or bait and OS's.
tl;dr practice pressure to objectively beat 2CC mashing, bait neutral 2CC, practice punish combos for blocked reversals and make sure your yomi is on point. Also, if he is predictable whith 2CC, shield/DP can help you too.
PS: you can low profile 22B with 2A/B/C oki if I'm not mistaken, so I didn't even acknowledge that as a reversal.
Maybe someone else (butterfree?) can provide better insights since it's been a while since I played C-7ya or that matchup, lol