Lightning Serpent

Trample, haste
This creature enters with X +1/+0 counters on it.
At the beginning of the end step, sacrifice this creature.

Mogg Maniac

Whenever this creature is dealt damage, it deals that much damage to target opponent or planeswalker.

Plains

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.

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.

Guilty Conscience

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

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Pariah

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

Mountain

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.

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.

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.)

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.