This is because Limited is full of creatures, and the removal that exists tends to be clunky (even good ones like Sephiroth's Intervention cost 4 mana)
Yes, if youre running a deck that uses the graveyard or you dont want to pay the Commander Tax, you can pop the creature into the graveyard until youre ready to exhume it
Attack with Ukkima, get its leave the battlefield ability when you ninjutsu in your real attacker, buff the Ninja with Cazur, rinse, and repeat
It is a card that captures Mewtwo's emotional core, that sense of being immensely powerful yet profoundly alone, in a way that few other card illustrations have managed to achieve across the entire history of the TCG
Players should be able to quickly understand the card during gameplay
The artwork will feature Mega Greninja and Mega Zeraora on the front and Mega Darkrai and Mega Chandelure on the back