There is no way this isn't a Mythic, right?
I could def see this as mythic, but I'm not 100% sure that's all it can be.
I like the idea a lot, but surely this is too abusable? Maybe it isn't, but it feels like if you can hit them with it at all, one repeatable "gain control of permanents you own" effect or one repeatable self-bounce effect gives you infinite turns.
Brooding Saurian probably breaks this. Turn to Mist is worrisome (but vastly less repeatable). Not convinced Unsummon is problematic without haste.
But if it does damage, you can bounce and replay that turn. Well, depending how much mana you spent to get it through the first time.