I was playing a game of Journey Down the Anduin, and Aragorn was defending against the Hill Troll with a copy of Blood of Numenor on him and a Steward of Gondor. The Hill Troll got a shadow effect that said that it got +2 attack. Aragorn had three damage already, and when he had triggered Blood of Numenor he had four resources left in his resource pool, giving him 6 defense against 8 attack. So, he would have died. But, I had a a copy of For Gondor! in my hand. Could I spend two out of the four resources to play For Gondor!, therefore giving Aragorn +1 defense, which is all he needs to survive? Or, does he lose 2 defense by spending two resources because of Blood of Numenor?
I guess my question is this: Does Blood of Numenor's effect happen immediately, counting all the resources that the hero has in his resource pool immediately and providing the extra defense based on that number, or can its effect be changed if you spend some of the resources that were there when the ability was triggered?