Flare Metal Dragon

+1: Search your library or graveyard for an instant or sorcery and put it into your hand. You may use it without paying its mana, but then exile it.
-5: Put X +1/+1 counters on target creature, where X is the number of spells the opponent has exiled.
-15: You get an emblem that says "You may cast spells that either player has exiled, as long as you can pay the mana cost. The spell stays exiled."