Well, you’ll mess up the additional turn order. And there can only be a total of five additional turns after time is called. You don’t get five turns plus any extra turns generated during those turns, you get a total of five additional turns to be shared by both players.
Let’s look at an example. Time has been called, and we have Player A and B still playing. The tentative turn order at this point is A, B, A, B, A. Let’s say that on turn 2, Player B gets an extra turn because of their Medomai. So now the total turn order looks like this: A, B, B, A, B. So instead of Player A getting the last turn, Player B will get the last turn.
In another example, let’s say we’re on turn 5 (i.e., the last turn of additional turns), and the active player once again attacks and deals damage with the Medomai. What happens? Well, at the end of the fifth turn, the game is over. It doesn’t matter if you have an extra turn generated by a spell or ability waiting, the game is over at the end of the fifth turn, so you effectively lose that extra turn.
Oh, and also, a bonus rules tip: in Magic, we define an extra turn as one generated by a spell or ability, not the additional turns granted at the end of a match. So Medomai can attack like normal during the additional five turns (unless one of those turns is an extra turn granted by Medomai’s triggered ability). In fact, Medomai is the reason there was a minor MTR update to clarify that the five turns are “additional” rather than “extra” at the end of the round!
Today’s Tournament Tip written by Nathan Long