Achillios, The Oathsworn

You may look at and reveal the top card of your library anytime.
You may play lands and cast spells from the top
of your library.
When you reveal the top card of your library
, choose one—
• {p/r}: Achillios deals 4 damage to any target.
• {p/g}: Duplicate— Mana cost of revealed card
(This ability can only be used once a turn)
• {p/u}{ut}: Counter target spell, draw a card