Arcanis, The Omniscient

Flying, Vigilance
This spell costs {1} less to cast for each instant
or sorcery you own in your graveyard or in exile.
Wizards you control get +1/+1 for each instant
or sorcery in your graveyard or in exile.
When Arcanis, The Omniscient attacks you may
cast an instant card you own from your graveyard
without paying its mana cost. If an instant cast
this way would go to your graveyard. exile it
instead.