Boros Reckoner

Whenever this creature is dealt damage, it deals that much damage to any target.
{R/W}: This creature gains first strike until end of turn.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Quest for Pure Flame

Whenever a source you control deals damage to an opponent, you may put a quest counter on this enchantment.
Remove four quest counters from this enchantment and sacrifice it: If any source you control would deal damage to a permanent or player this turn, it deals double that damage to that permanent or player instead.

Lightning Helix

Lightning Helix deals 3 damage to any target and you gain 3 life.

Ollenbock Escort

Vigilance
Sacrifice this creature: Target creature you control with a +1/+1 counter on it gains lifelink and indestructible until end of turn.

Loran's Escape

Target artifact or creature gains hexproof and indestructible until end of turn. Scry 1.

Spitemare

Whenever this creature is dealt damage, it deals that much damage to any target.

Furnace of Rath

If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.