Isamaru is one such card
The set usually includes three foil cards and over sixty cards, including Trainer Cards, Energy Cards, Pokmon EX, Mega EX, Pokemon-GX, and other cards
Primarily sticking to blue, black, and green cards, plus one red outlier, these can slot into a wide variety of situations and decks, generally with very little setup needed to play them other than getting past a few turns and casting a healthy number of spells
Theres also a visual appeal that might account for this, but the highest factor is the weighing aspect
The holo on the darker background always creates a cool effect
This served as a sort of prologue to the Gatewatch storylines that carried players through the next few years worth of sets and stories