Stringbound, God of Yo-Yos

Indestructible
Whenever you cast an instant or sorcery spell,
you may pay five life. If you do, that instant or
sorcery spell gains rebound. (Exile the spell as it resolves if you cast it from your hand. At the
beginning of your next upkeep, you may cast that card
from exile without paying its mana cost.)
Whenever you cast a spell from exile, draw a card.