(1/19/2018) If an effect asks how many cards are in your graveyard, use the total number of cards in all your graveyards
During the End Phase: Target 1 "Red Dragon Archfiend" in your Graveyard
Its a little worse in Commander since you cant sideboard it in or play multiple copies, but protecting your team from countermagic and blue and black spells for a turn while potentially drawing a card often feels like a blowout
'Claims' means all sums of money, debts, dues, suits, actions, causes of action, proceedings, arbitrations, claims, accounts, liabilities, losses, demands, costs, expenses, notices or any other type of claim howsoever arising out of these Conditions or anything relating to the subject matter of these Conditions
Others are niche tools in specific formats, but they are still powerful and crucial to the gameplan of some decks