Thoughtseize came out in Lorwyn and quickly became the gold standard for targeted discard, often feeling like a straight upgrade over older options like Duress
Gravelgill Axeshark, in addition to having at least one persons favorite card name ever (see TapTapConcede , Episode 1 starting around 29:30), can stall the game until you build up enough card advantage, the combo, or enough unblockable damage, can provide a persistent beater, or can allow Voidwalk to almost act as a Stolen Identity when comboing with Wanderwine Prophets
When Pokemon blew the doors off, we said, "OK, the genre's working, what do we have to fit?" Digimon floated to the top
Lots of these cards have special art but the normal frame, or maybe a retro frame, or perhaps a special foiling over a normal frame
Purphoros, God of the Forge could also very easily be in this slot as well
But, trading card players will have to carefully consider when they will try to activate the Mega Evolution, as it immediately ends their turn, with no chance to attack until it is their turn again