So this came up as a topic a couple days ago, and I want to make sure I have the right of it. So my friend was curious on if he was able to play another unique enhancement after one was stolen by the opposing player. For clarification and example, he plays Echo Base, which is a unique enhancement. I take it with Utinni! so it is under my control. Because it is unique, he can't put another out. My line of reasoning for this goes to 2 vs 2 matches where players are not allowed to have more than one of the same unique character out in play(i.e. Darth Vader).
One of the other questions that came up was how late in someone's turn can someone do things like assigning the one point of damage if the Balance of the Force is on the Light Side, Council of the Sith - Reaction: After your opponent's turn begins, draw 1 card, and other effects of that nature.