Tenebris, Who Foresees Doom

Whenever a creature an opponent controls attacks you, you may pay {1}. If you do, sight X, where X is Tenebris' power. (To sight X, look at the bottom X cards of your library, then put any number of them on top of your library and the rest
on the bottom in any order.)
{t}: Reveal the top two cards of your library. Destroy target creature with converted mana cost less than the combined converted mana
cost of the revealed cards.