Calibrated Blast

Calibrated Blast goes on the stack without a target. When you reveal a nonland card during its resolution, its reflexive triggered ability triggers and you pick a target to be dealt damage. You'll know the mana value of the revealed nonland card and how much damage will be dealt.

You must still follow any timing restrictions and permissions, including those based on the card's type. For instance, you can cast a sorcery using flashback only when you could normally cast a sorcery.

A spell cast using flashback will always be exiled afterward, whether it resolves, is countered, or leaves the stack in some other way.