Shriekwood Devourer

Trample
Whenever you attack with one or more creatures, untap up to X lands, where X is the greatest power among those creatures.

Assault Suit

Equipped creature gets +2/+2, has haste, can't attack you or planeswalkers you control, and can't be sacrificed.
At the beginning of each opponent's upkeep, you may have that player gain control of equipped creature until end of turn. If you do, untap it.
Equip {3}

Evercoat Ursine

Trample
Hideaway 3, hideaway 3 (When this creature enters, look at the top three cards of your library, exile one face down, then put the rest on the bottom in a random order. Then do it again.)
Whenever this creature deals combat damage to a player, if there are cards exiled with it, you may play one of them without paying its mana cost.

Meltstrider's Resolve

Enchant creature you control
When this Aura enters, enchanted creature fights up to one target creature an opponent controls. (Each deals damage equal to its power to the other.)
Enchanted creature gets +0/+2 and can't be blocked by more than one creature.

Alpha Authority

Enchant creature
Enchanted creature has hexproof and can't be blocked by more than one creature.

The Eternal Wanderer

No more than one creature can attack The Eternal Wanderer each combat.
+1: Exile up to one target artifact or creature. Return that card to the battlefield under its owner's control at the beginning of that player's next end step.
0: Create a 2/2 white Samurai creature token with double strike.
−4: For each player, choose a creature that player controls. Each player sacrifices all creatures they control not chosen this way.

Godsend

Equipped creature gets +3/+3.
Whenever equipped creature blocks or becomes blocked by one or more creatures, you may exile one of those creatures.
Your opponents can't cast spells with the same name as a card exiled with Godsend.
Equip {3}

Familiar Ground

Each creature you control can't be blocked by more than one creature.

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.

Bow of Nylea

Attacking creatures you control have deathtouch.
{1}{G}, {T}: Choose one —
• Put a +1/+1 counter on target creature.
• Bow of Nylea deals 2 damage to target creature with flying.
• You gain 3 life.
• Put up to four target cards from your graveyard on the bottom of your library in any order.

Nature's Will

Whenever one or more creatures you control deal combat damage to a player, tap all lands that player controls and untap all lands you control.

Angelic Guardian

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever one or more creatures you control attack, they gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

Mirri, Weatherlight Duelist

First strike
Whenever Mirri attacks, each opponent can't block with more than one creature this combat.
As long as Mirri is tapped, no more than one creature can attack you each combat.

Dueling Grounds

No more than one creature can attack each combat.
No more than one creature can block each combat.

Vorrac Battlehorns

Equipped creature has trample and can't be blocked by more than one creature.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Outland Colossus

Renown 6 (When this creature deals combat damage to a player, if it isn't renowned, put six +1/+1 counters on it and it becomes renowned.)
This creature can't be blocked by more than one creature.