In addition to their limited set appearances, Shining, Gold Star and Shiny Vault cards have a history of having extremely low pull rates
It's probably too good for a one spell per turn format
Brawl Not Legal Vintage Legal Timeless Not Legal Commander Legal Pauper Not Legal Oathbreaker Legal Penny Legal Toolbox Notes and Rules Information for Coat of Arms: If a creature has more than one creature type, and one of those types matches the creature you are calculating for, then count that creature
If Pokemon makes Evolving Skies booster boxes more accessible, the price of these cards could come down to make them more obtainable
But I also want to look out for cards that were excluded from the precon, like Ebonblade Reaper, which can drastically change an opponents place in the game, or Primordial Mist, which can turn manifested instants or sorceries back into spells