Consummate Researcher

Commander creatures you own have "The first
instant or sorcery spell you cast during each of your
turns has discover X, where X is twice the number
of times you’ve cast your commander from the
command zone this game." (Exile cards from the
top of your library until you exile a nonland card
with that mana value or less. Cast it without paying
its mana cost or put it into your hand. Put the rest
on the bottom in a random order.)