Winterthorn Blessing

What reads as a modest tempo trick is really combining two effects green and blue rarely bundle into one card: it grows a creature while removing one of the opponent's from a full turn cycle of combat. The freeze clause is the engine, and it works because the target "doesn't untap during its controller's next untap step": cast it before your attack to disable a blocker, and that same creature stays tapped through the crackback, so a single casting effectively subtracts a body from two combats. Both halves are independent (up to one target creature you control, up to one you don't), so it degrades gracefully into a pure removal-of-one-blocker effect when you have nothing worth pumping, or into a straight +1/+1 counter when the opposing board is empty. Flashback is what pushes it from a fine two-drop into an attrition tool: casting it a second time out of the same card buys another turn of tempo swing and, potentially, a second counter stacked on a threat you want to see through. The constraint that keeps it honest is that both castings are sorcery-speed. This is proactive tempo, not reactive interaction: it asks you to commit ahead of the swing and lean on the untap-lock to hold the ground you took on the way back. It is a build-around for aggressive creature decks that want their attacks to keep paying off, not a card that saves you at instant speed.