Power Surge [Unlimited Edition] Oath of the Gatewatch Prerelease Promos you may exile an instant

you may exile an instant card with mana value 2 or less from your hand

Set: Aether Revolt Type: Artifact Creature — Construct Rarity: Rare Cost: {X}{X} Walking Ballista enters the battlefield with X +1/+1 counters on it

Set: Kaladesh Inventions Type: Artifact Rarity: Mythic Cost: {X}{X} Chalice of the Void enters the battlefield with X charge counters on it

instead you may skip that draw

Elder Spawn can't be blocked by red creatures

Power Surge [Unlimited Edition] Oath of the Gatewatch Prerelease Promos you may exile an instantSet: Unlimited Edition Type: Enchantment Rarity: Rare Cost: {R}{R} At the beginning of each player's upkeep, Power Surge deals X damage to that player, where X is the number of untapped lands they controlled at the beginning of this turn.