Once that happens, the value of X wont change later in the turn even if Gruul Beastmasters power changes
There may not have been any way to save the format, but making the format look more like Standard definitely wasnt the way to do it
In the endgame, when both players are looking for lethal, being able to safely attack your opponent is a powerful tool to have.
Later in the game you should be able to pay the escape cost, especially if you have any amount of self-mill (dredge, Im looking at you)
I once received a stack of proofs for another artist, and then had to forward them along
As long as you lower the curve of your spells, which you need to do in cEDH anyway, if you cast a card that targets Stella and untaps it, youve got an infinite loop of tapping, untapping and spell-copying