Brash Taunter

Indestructible
Whenever this creature is dealt damage, it deals that much damage to target opponent.
{2}{R}, {T}: This creature fights another target creature.

Pariah

Enchant creature
All damage that would be dealt to you is dealt to enchanted creature instead.

Star of Extinction

Destroy target land. Star of Extinction deals 20 damage to each creature and each planeswalker.

General's Regalia

{3}: The next time a source of your choice would deal damage to you this turn, that damage is dealt to target creature you control instead.

Stuffy Doll

Indestructible
As this creature enters, choose a player.
Whenever this creature is dealt damage, it deals that much damage to the chosen player.
{T}: This creature deals 1 damage to itself.

Lightning Helix

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

Shivan Meteor

Shivan Meteor deals 13 damage to target creature.
Suspend 2—{1}{R}{R} (Rather than cast this card from your hand, you may pay {1}{R}{R} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Stensia Uprising

At the beginning of your end step, create a 1/1 red Human creature token. Then if you control exactly thirteen permanents, you may sacrifice this enchantment. When you do, it deals 7 damage to any target.

Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Fatal Attraction

Enchant creature
When this Aura enters, it deals 2 damage to enchanted creature.
At the beginning of your upkeep, this Aura deals 4 damage to enchanted creature.

Truefire Captain

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Whenever this creature is dealt damage, it deals that much damage to target player.

Tower of Calamities

{8}, {T}: This artifact deals 12 damage to target creature.

Spitemare

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

Volcano Hellion

This creature has echo {X}, where X is your life total. (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When this creature enters, it deals an amount of damage of your choice to you and target creature. The damage can't be prevented.

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.

Livewire Lash

Equipped creature gets +2/+0 and has "Whenever this creature becomes the target of a spell, this creature deals 2 damage to any target."
Equip {2}

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Rip Apart

Choose one —
• Rip Apart deals 3 damage to target creature or planeswalker.
• Destroy target artifact or enchantment.

Firesong and Sunspeaker

Red instant and sorcery spells you control have lifelink.
Whenever a white instant or sorcery spell causes you to gain life, Firesong and Sunspeaker deals 3 damage to target creature or player.

Guilty Conscience

Enchant creature
Whenever enchanted creature deals damage, this Aura deals that much damage to that creature.