First, most overpowered cards are still overpowered when they're restricted, so, in formats where there are only a few restricted cards, all that restricting overpowered cards serves is to add randomness to the game
Theyve each been found in a different part of the world
Get access to your cards when attacking so you can cast more spells before passing the turn
This means you can chump block with your tentacles and have a 9/9 commander early in the game
If heads, take a (lighting) energy from your Energy Zone and attach it to one of your benched (lightning) Pokmon." It's as simple as you get, and specialization cards can be extremely strong, especially given that Bellibolt ex is a current meta card
Outside of Cephalid Facetaker and Aboshan, Cephalid Emperor, this MTG creature type was fairly lackluster