Reminiscent of Undermine or Countersquall. But with flashback. I fear countermagic with flashback is just a bit too good; you'll note that Fervent Denial was costed through the roof and back, and Innistrad block revisited flashback without printing a single flashback counterspell.

­Fervent Denial was way overcosted because Counterspell was already too good, and they couldn't push much countermagic. I did a flashback Cancel (also called (((Fervent Denial)))) with what I believe is a fair flashback cost (not on the file as of now).

I might tweak some numbers here and there after I've tested this, but the idea is good enough. It is very powerful anyway but I'll probably have to push blue-red decks a bit, and this card's design also fits in and inspires a whole deck (counter spells + burn spells) that might not be obvious to many people who want to try blue-red. The power of multicolored cards is also a bit higher than what's "safe" here.

To adjust the card in power, this became a choose one, with a less intensive cost and a cheaper flashback cost. It's still pretty good.