An alternate take on Negate_, which more or less coincidentally also uses an existing name - Rewind.

The wording here does look kinda silly. The effects can't go in the other order though, because "end the turn" exiles all spells including the currently-resolving spell.

Use this on your opponent's upkeep. Fun times for all.

I like the idea. But I'm not sure how to channel it towards "interesting" uses, as opposed to simply playing it in your end step to get an extra turn (or playing it your opponent's upkeep to get TWO extra turns, unless it's changed to say "active player").

Yeah, this is just Time Stretch right now.

Sorcery speed? I guess that's mostly Time Warp, though...

Instant speed with "You may only cast this spell during your turn." That should give you a reason to cast it instead of Time Warp. It stops something you don't like and begins the turn again. Still would probably cost at least , though.

Eep! This was meant to have "cast only during your turn", indeed. Not sure how I forgot that.

Would it be more interesting if it said "The active player takes an extra turn after this one"? It probably would, wouldn't it?

I can't quite remember what I was thinking (I've been so exhausted recently), but I think I was wanting it to require something to undo. How about if "Cast ~ only if you control a spell or nonmana ability on the stack?"

I think what you're going for is good, but I'm not sure if there's a way that works in the rules or not.

Maybe something like "End the turn, then the active player takes an extra turn after this one, skipping all phases which have already begun this turn"?

Or maybe skip phases which have completed, both have drawbacks. But that at least removes a certain amount of "get it twice", while still acting as "stop that right now". Or maybe it still needs "your turn only" as well, but that would simplify it.

Alex: Hope you're ok!