Black Skull Dragon is treated as an Archfiend, with a whopping 3,200 ATKand itll get even stronger with the right Spells or Bonuses in play
I know that no one likes hearing stupid background details of how I do things, but in my word processor of choice I just duplicated my chapter for Nokta Games Supermarket Simulator
And each type of energy powers specific attacks and abilities
This means you could run two copies of a card in decks sized from 1 to 20, while decks at 60 cards or more could run unlimited copies of any given card
If you got three of them together, like Mew, Pidgeot, and Onyx, you could see a complete picture between the three of them
Not only is it a pretty intimidating creature, sporting flash, flying, and a 4/2 base stat, but it also gives all of its controllers' spells flash