I've been playing Magic for about six months and thought I had a decent handle on how things work until I ran into the following problem:
Set-up: I was playing mono black devotion against blue-green control. I bestowed Herald of Torment onto Pharika Chosen. At the end of my turn, my opponent (in control of Prophet of Kruphix) flashed in a Siren of the Fanged Coast. I chose not to pay the tribute, so my opponent took my Pharika Chosen with Herald of Torment attached.
Question: If I kill Pharika Chosen while my opponent controls it, when Herald of Torment becomes a creature again do I regain control of Herald of Torment, or does my opponent retain possession of it?