Ball Lightning

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice this creature.

Lightning Skelemental

Trample, haste
Whenever this creature deals combat damage to a player, that player discards two cards.
At the beginning of the end step, sacrifice this creature.

Coalstoke Gearhulk

Menace, deathtouch
When this creature enters, put target creature card with mana value 4 or less from a graveyard onto the battlefield under your control with a finality counter on it. That creature gains menace, deathtouch, and haste. At the beginning of your next end step, exile that creature.

Carnage, Crimson Chaos

Trample
When Carnage enters, return target creature card with mana value 3 or less from your graveyard to the battlefield. It gains "This creature attacks each combat if able" and "When this creature deals combat damage to a player, sacrifice it."
Mayhem {B}{R}

Alesha, Who Laughs at Fate

First strike
Whenever Alesha attacks, put a +1/+1 counter on it.
Raid — At the beginning of your end step, if you attacked this turn, return target creature card with mana value less than or equal to Alesha's power from your graveyard to the battlefield.

Kratos, God of War

Double strike
All creatures have haste.
At the beginning of each player's end step, Kratos deals damage to that player equal to the number of creatures that player controls that didn't attack this turn.