The majority of the time, you’re probably going to be using Celestial Flare before damage goes through: for example, when your opponent attacks you with his biggest creature you can just throw out Flare right away to get rid of his biggest baddest beater BEFORE it manages to bring the pain to you or your own creatures. Likewise, you can use it to clear out his only blocker and save your attacking creature before damage. But, the thing with Flare is that you don’t pick what gets sacrificed; your opponent does. So why bother with it if they have little dudes to feed to your Flare? That’s where knowing the rules can help you!
A creature remains “attacking” or “blocking” for the entirety of combat. When I attack you with my creatures, they’re still considered “attacking creatures” until we move into a new step, so that includes after damage has already happened. So, let’s say I attack you with a few 1/1 Saprolings, and the Sporemound that made them. You throw some 2/2 bodies in front of the tokens, and take the 3 from Sporemound. Then, AFTER damage you cast Celestial Flare, and I only have one attacking creature to sacrifice: Sporemound! This works on either end of the combat, to get rid of attackers or blockers. Either way, it’s a legal (and sometimes smart) move to use Flare after damage has weeded out the smaller creatures, to try and get rid of the bigger targets.
Today’s Rules Tip written by Trevor Nunez