Reanimate would resolve and drain you before the Demon is in play I am pretty sure.
You resolve cards in the order it reads. Thus the creature is put in play then you pay the life. I’m no rules expert but I think it works. I smell 2 mana draw 8.
Oh yeah *****
12/7/2018 You lose life after the creature is already on the battlefield. Any abilities it has that interact with loss of life, such as that of Platinum Emperion, apply to that loss of life.
Oh yeah *****
LOL + Sylvan Library