msem-instigator

Sacrifice another creature: Brash Hunter deals 1 damage to any target.
At the beginning of your end step, if three or more creatures died this turn, transform Brash Hunter.

Alpha (You may have this creature enter with a +1/+1 counter on it. If you do, it becomes alpha and can only attack alone.)
Brazen Chimera can't be blocked except by three or more creatures as long as it has a +1/+1 counter on it.

Trample
Canyon Agamid can't block creatures with power 2 or less.

Tithe (When this creature enters, you may tap three other artifacts and/or creatures you control.)
When Cataclysmic Preacher's tithe is paid, return target instant or sorcery card from your graveyard to your hand.

Flying
Vanishing 3 (This creature enters with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
If Chronowing Phoenix would die while it had no time counters on it, instead exile it, then return it to the battlefield.

Menace
Sacrifice another creature: Corpulent Gibberer deals 1 damage to any target.
Evoke {1}{R} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

First strike
Whenever Creed, Eternal Straggler attacks, exile the top card of your library. You may play that card this turn, and that spell costs {2} less to cast.

Flying, haste
When Crimson Hellmaw enters, it deals 3 damage to any target.
Revive {5}{R}{R} ({5}{R}{R}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

When Crystal Vision Abomination enters, create a 1/1 blue Elemental creature token with flying.
Whenever an Elemental you control attacks, that creature gets +1/+0 and first strike until end of turn.

Flying
Whenever you make first contact, Curio Hellkite deals 2 damage to any target. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)

You may exert Deathmarked Explorer as it attacks. When you do, it gets +X/+X until end of turn, where X is 10 minus your life total. (An exerted creature won't untap during your next untap step.)
{T}, Discard a card: Draw a card. Deathmarked Explorer deals 2 damage to you.

Menace
Creatures you control get +1/+0 as long as you've foretold a card this turn.
Creatures you control get +1/+0 as long as you've cast a foretold spell this turn.

Frenzy 3 (Whenever this creature attacks and isn't blocked, it gets +3/+0 until end of turn.)
Other red creatures you control have frenzy 2. (If a creature has multiple instances of frenzy, each triggers separately.)
Other creatures you control have frenzy 1.

Dreamchaser Djinni attacks each combat if able.

Assault {1}{R} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
Whenever a creature you control assaults, creatures you control get +1/+0 until end of turn.

Your opponents can't gain life.
Whenever you cast a noncreature spell, put a +1/+1 counter on Eidolon of the Arena.

Flying, haste
Whenever Emissary of Antiquity deals combat damage to a player, you may cast an instant or sorcery spell with mana value 3 or less from your hand without paying its mana cost.

Haste
Whenever Emonoru, Ema's Wings attacks alone, he gains flying and double strike until end of turn.

Explosion Fanatic can't attack unless an opponent was dealt damage this turn.

Enchant creature
Embody (Enchanted creature is a copy of this card except for its types.)
Whenever Fate of the Brave becomes tapped, it deals 1 damage to each opponent.

Haste
{1}{W}: Fellor Heartstriker gains lifelink until end of turn.

At the beginning of combat on your turn, you may have target artifact you control become a 3/3 artifact creature until end of turn. If you do, it and Field Engineer attack this turn if able.

Reach
Whenever you cast a noncreature spell, you may pay {R}. If you do, target creature can't block this turn.

When Frostfield Swordsman enters, arm it. (Create a colorless Equipment artifact token with “Equipped creature gets +1/+0” and equip {2}, then attach it to that creature.)

When Giku Weaponsmith enters, create two colorless Equipment artifact tokens with “Equipped creature gets +1/+1” and equip {1}.