Cosmic Hunger

Target creature you control deals damage equal to its power to another target creature, planeswalker, or battle.

Devouring Tendrils

Target creature you control deals damage equal to its power to target creature or planeswalker you don't control. When the permanent you don't control dies this turn, you gain 2 life.

Apex Altisaur

When this creature enters, it fights up to one target creature you don't control.
Enrage — Whenever this creature is dealt damage, it fights up to one target creature you don't control.

Infectious Bite

Target creature you control deals damage equal to its power to target creature you don't control. Each opponent gets a poison counter.

Erinis, Gloom Stalker

Deathtouch
Whenever Erinis attacks, return target land card from your graveyard to the battlefield.
Choose a Background (You can have a Background as a second commander.)

Master's Rebuke

Target creature you control deals damage equal to its power to target creature or planeswalker you don't control.

Bonds of Mortality

When this enchantment enters, draw a card.
{G}: Creatures your opponents control lose hexproof and indestructible until end of turn.

Bite Down

Foe-Razer Regent

Flying
When this creature enters, you may have it fight target creature you don't control.
Whenever a creature you control fights, put two +1/+1 counters on it at the beginning of the next end step.

Ulvenwald Tracker

{1}{G}, {T}: Target creature you control fights another target creature.

Heart's Desire

Create a 1/1 white Human creature token. (Then exile this card. You may cast the creature later from exile.)

Lovestruck Beast

This creature can't attack unless you control a 1/1 creature.

Lovestruck Beast // Heart's Desire

Agent of the Shadow Thieves

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, put a +1/+1 counter on this creature. It gains deathtouch and indestructible until end of turn."

Spiritmonger

Whenever this creature deals damage to a creature, put a +1/+1 counter on this creature.
{B}: Regenerate this creature.
{G}: This creature becomes the color of your choice until end of turn.

Contest of Claws

Target creature you control deals damage equal to its power to another target creature. If excess damage was dealt this way, discover X, where X is that excess damage. (Exile cards from the top of your library until you exile a nonland card with that mana value or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Curse of the Werefox

Create a Monster Role token attached to target creature you control. When you do, that creature fights up to one target creature you don't control. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1 and has trample. Creatures that fight each deal damage equal to their power to the other.)

Undercity Uprising

Creatures you control gain deathtouch until end of turn. Then target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

Cartouche of Strength

Enchant creature you control
When this Aura enters, you may have enchanted creature fight target creature an opponent controls. (Each deals damage equal to its power to the other.)
Enchanted creature gets +1/+1 and has trample.

Feral Encounter

Look at the top five cards of your library. You may exile a creature card from among them. Put the rest on the bottom of your library in a random order. You may cast the exiled card this turn. At the beginning of the next combat phase this turn, target creature you control deals damage equal to its power to up to one target creature you don't control.

Ram Through

Target creature you control deals damage equal to its power to target creature you don't control. If the creature you control has trample, excess damage is dealt to that creature's controller instead.