Crimson Flash is unsafe on block (-6, -7, and -8 for lk, mk, and hk respectively). Your punish options just come down to distance, but pp (passion press (f/b.mp)) should usually work. The EX version is -2, so you should be able to take your turn back with s/c.lp.
Edit: a good claw player won’t give you this opportunity often (if at all).
It would make sense that you can V-reversal his CA as Mika is strike and projectile invulnerable for the first 28 frames of her V-reversal. A decent claw player isn’t going to do his CA in this kind of situation though.
You can V skill his super =) enough said. also alpha counter his rolls and get a free knock down on his ass. You can punish his m and H rolls with s. MP to combo or the faster option S.lk hell you can command grab his Ex if you scout it.