msem-instigator

Menace
Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)

You may exert Accursed Bear as it attacks. When you do, it gets +1/+0 and gains trample until end of turn. (An exerted creature won't untap during your next untap step.)

Menace, haste
Whenever Aiel's Fury attacks, scry 2, then reveal the top card of your library. Aiel's Fury gets +X/+0 until end of turn, where X is that card's mana value.

Haste
{R}: Akoum Rockhurler gets +1/+0 until end of turn.
Whenever Akoum Rockhurler attacks, you may sacrifice a land. If you do, put two +1/+1 counters on Akoum Rockhurler.

At the beginning of your upkeep, you may sacrifice a Goblin. If you do, Alenian Boom Squad deals 2 damage to any target.

Whenever Apprehensive ‘Slinger deals combat damage to a player or planeswalker, you may discard a card. If you do, draw a card.

Other creatures you control can't attack or block alone.

Whenever Arcane Metalcrafter or another Wizard you control attacks, create a 1/1 colorless Construct artifact creature token that's tapped and attacking.
Whenever a Construct you control dies, Arcane Metalcrafter deals 1 damage to each opponent.

Whenever Arena Challenger deals damage to a creature, upgrade it. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• First strike
• Prowess

As long as Armed Vendor is enchanted or equipped, it gets +1/+0 and has menace.

Whenever you cast an Inscription spell, you may choose target creature you control. If you do, as that Inscription resolves, exile it inscribed onto that creature instead of putting it anywhere else.

Whenever Aspect of An'yama attacks, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
Spells you cast from your graveyard, activated abilities of cards in your graveyard, and reprise costs of spells you cast cost {1} less.

{1}, Sacrifice a creature or enchantment: Exile the top card of your library. You may play that card this turn.

Menace, haste

Haste
Whenever Banished Companion attacks, it deals 2 damage to you.

Trample
Whenever another Dwarf you control enters, create a colorless artifact token named Ale. It has “{T}, Sacrifice this artifact: Target creature gets +2/+0 until end of turn. Activate only as a sorcery.”

Flying
Menagerie — When Bleakrealm Mini-Menace enters, if there are five or more creature types among creatures you control, it deals 2 damage to target opponent and 2 damage to up to one target creature or planeswalker that player controls.

At the beginning of each player's end step, if they aren't horrific, Bloody Valentine deals 2 damage to that player. (You're horrific as long as you've sacrificed a permanent or discarded a card this turn.)

Whenever another creature you control enters, you may have it gain haste. If you do, return it to its owner's hand at the beginning of the next end step.

Menace
When Bogborn Exorcist enters, you may discard a card. When you do, exile target instant or sorcery card with mana value 3 or less from an opponent's graveyard. Copy that card. You may cast the copy without paying its mana cost.

Damage can't be prevented.
At the beginning of your upkeep, Bomb Juggler deals 3 damage to target player chosen at random.

First strike
Whenever you cast an instant or sorcery spell, if Branch Breaker dealt combat damage to a player this turn, you may sacrifice Branch Breaker. If you do, copy that spell. You may choose new targets for the copy.

Haste
Whenever one or more creatures attack, you may discard a card. If you do, draw a card.

Haste
{T}: Discard a card, then draw a card.
Paranoia {2}{R} (You may cast this spell for its paranoia cost when a permanent you control leaves the battlefield.)

Creatures you control have haste and attack each combat if able.
Attacking Soldiers you control get +1/+0.