I don't know if this would ever matter, but I'm curious how it works. One player has Roil Elemental out and plays a land, triggering its ability to take control of another player's creature. In response to the trigger going on the stack, the other player destroys Roil Elemental. I know the second player is going to end up with his own creature in the end, but what I'm wondering is does the creature change sides momentarily? Or does the destruction of Roil Elemental somehow keep the creature from ever being taken?