rebound question: don't you have to target as soon as they go on the stack? meaning they go on the stack at the same time and the first ephemerate fizzles the other one since its the same target?
both triggers of rebound go on the stack you choose to resolve the first one allowing you to cast ephem1 for free with target then after that is all done (with any etbs) the second rebound on the stack is now able to resolve allowing you to cast ephem2