"Bolters? Chainswords? All fine weapons, however I wield a far more dangerous power."

Epistolary Librarian

Veil of Time — Whenever Epistolary Librarian attacks, you may cast a spell with mana value X or less from your hand without paying its mana cost, where X is the number of attacking creatures.

Veil of Time — Whenever this creature attacks, you may cast a spell with mana value X or less from your hand without paying its mana cost, where X is the number of attacking creatures.