As an additional cost to cast Titan's Presence, reveal a colorless creature card from your hand.
Exile target creature if its power is less than or equal to the revealed card's power.
8/25/2015 The colorless creature card stays revealed until Titan’s Presence leaves the stack.
8/25/2015 The colorless creature card you reveal doesn’t have to still be in your hand as Titan’s Presence resolves. If it’s not, use its power as it last existed in your hand.
8/25/2015 Check the target creature’s power as Titan’s Presence resolves to see if it’s less than or equal to revealed creature card’s power. If it’s greater, Titan’s Presence will finish resolving with no effect.