Ocinot, Lord of Dementia

When Ocinot, Lord of Dementia enters the
battlefield, you may exile target instant or sorcery
card from your graveyard or hand and put a
grimoire counter on it.
Discard a card with converted mana cost X:
Copy target spell you own in exile with a grimoire counter that has converted mana cost X, you may
cast the copy without paying the mana cost.