I use Radiant Archangel in a deck full of flying creatures. It is a 3/3 flyer with +1/+1 for each other flying creature in play. During a game, I had seven other flying creatures, making it a 10/10. My opponent cast a spell (and I'm sorry I don't recall the spell) that did 6 damage to all my creatures.
He contends that this kills Radiant Archangel as well because the static bonus of +1/+1 for all the flying creatures in play goes away once they are dead and the damage sticks around until the end of turn. Thus, after the spell resolves, the other flying creatures are gone so Radiant Archangel is only a 3/3, and it has 6 damage so it's dead.
I contend that when the damage was dealt, it was a 10/10 and survived the attack, and that the 6 damage can come out of the +1/+1 bonuses that the other flying creatures provided and that it lost once they were gone.
Does anybody have any official rulings on this?