The five colours, in addition to characterizing specific terrains and specific fantasy types, would also correspond to the strategies of certain colours from a gameplay mechanic -- the type of ways they would win, the types of counter-abilities they could do, and the flavour of the characters associated with them
A card like Skyshroud Ridgeback could come down early and attack and block productively, but only for a couple of turns, and the threatening Skyshroud Behemoth could be chump blocked for the scant two turns it was able to attack
It's not necessary to loop Lark over and over if you have things like Acidic Slime or Nekrataal coming back and forth
It's based on their rarity, condition, and popularity
Birgi, God of Storytelling / Harnfel, Horn of Bounty Want a fantastic combo piece that can help you go off out of nowhere