Artorias the Abysswalker

You may cast Artorias the Abysswalker from
your graveyard, but not from anywhere else.
As long as Artorias is on the battlefield, you may
cast Knight spells from your graveyard.
When Artorias dies, you lose 2 life.
Artorias had an unbendable will of steel, which both
helped and fed his hatred for servants of the Dark.