Mewtwo (Black Star Promo #12 and #14) represent the early promotional era of the Pokemon TCG, when cards were distributed through an eclectic and sometimes bewildering array of channels including magazines, mail-order promotions, league participation rewards, and retail partnerships
Personally, though, I've long wanted to build a mountains-matter mono-red deck with cards like Koth, Fire of Resistance, but there aren't really enough relevant cards to make it work
The biggest problem with Epic Struggle is that it does nothing until it wins the game
The ceiling for enters-the-battlefield effects you can get all at once here is pretty insane, especially when you combine this effect with Isshin, Two Heavens as One and Port Razer to trigger it multiple times per turn
Maybe its worth just playing to have removal in the command zone, but I want more than that out of an eight-mana creature
You can quickly see which numbers you need to finish a set