Jonrir, Seventh Wonder

Flying, hexproof
Whenever you cast your seventh spell each turn,
you may choose target instant or sorcery card in
your graveyard and exile it. If you do, you may
cast any number of artifact, instant, or sorcery
cards from your graveyard with a total mana
value of seven or less.
{7}, {t}: The next instant or sorcery spell you cast
this turn deals 7 damage to any target.