Once Scrambleverse starts to resolve, no player may respond until it has finished resolving. For example, you can’t wait to see who will control a creature before deciding whether or not to activate one of its abilities.
2011-09-22 • wotc
For each nonland permanent, any player may be randomly chosen, including the permanent’s current controller.
2011-09-22 • wotc
All of the control-change effects happen at the same time.
2011-09-22 • wotc
Each nonland permanent will untap, no matter which player was randomly chosen to gain control of it.
2011-09-22 • wotc