The design was probably intended to fight decks that draw many cards, but it quickly became a meta-warping card thats often in ban-worthy discussions
As a creature, an effect like this opens up synergy with cards like Woodland Bellower, Sun Titan, Panharmonicon, and clones like Phantasmal Image to reuse or duplicate the effect
Regardless of the card's flavor, it's utility in the right Commander build has supported this card's $7 price tag for some time now
a2b-35-giratina-ex's Chaotic Impact deals 130 damage to the opponent's Active Pokemon but will also damage a2b-35-giratina-ex for 20 damage
Once you get to Indigo Plateau, you'll need to defeat the Elite Four and the Champion to become the very best like no-one ever was
After that, the early sets (OP01) hold strong because of nostalgia and the original chase list