It would be on a tier with a secret rare or gold star depending on what kind of 1st ed card you nabbed randomly in your packs
Is six mana for a removal spell or a 4/4 vanilla creature a bad rate
Effects that make a temporary token copy of another creature like Splinter Twin, Saheeli Rai, and Feldon of the Third Path work favorably with end the turn effects
This is the same one I've been adding to all my Budget Commander deck over the years: lands and ramp, usually a 3713 split 50 mana
Throw in a few pieces like Losheel, Clockwork Scholar and Archangel of Tithes to make blocking even harder, and youll win in no time
Either way, both decks listed below require that you have at least two Mewtwo ex, which you should hopefully have before too long if you continue opening Genetic Apex Mewtwo booster packs