Let's say my opponent is controlling one of my creatures. And then I target that creature with Cast Out or Hostage Taker's ability. After the ability resolved, Cast Out or Hostage Taker leaves the battlefield. Would the creature return to the battlefield under my control?
My guess is it would return under its owner's control. Since card that moves from one zone to another becomes a new object with no memory, there is no difference between (1) using cast out on my creature under my control and (2) using cast out on my creature under my opponent's control. In the first case it is easy to see that the creature would return to the battlefield under my control when cast out leaves the battlefield, and both cases are actually the same.