Trainer's Pokmon cards have a history that dates back to the early Pokmon TCG days when Wizards of the Coast released two sets focused on the gym leaders of the Kanto region
In case Arcades is removed, his Commander deck has cards like Assault Formation to keep the defenders online, and the deck can even "flicker" its defenders so ETB effects like Arcades' own can be used all over again
It slows down decks that try to cast multiple spells in one turn like Storm, Tron, or Cascade, and it also messes with greedy mana production
It's designed to roll with the punches, dealing out damage while surviving attacks, and benefitting from support like healing cards
Some could get printed as filler in some sets, but who cares if we get something like Shorecomber Crab in paper Magic
The Pokmon Company has confirmed that Pokmon TCG Live will have cross-platform play during the beta and that players will still have access to Pokmon TCG Online while participating