msem-instigator

When Fleshcage Shambler dies, create a 2/2 colorless Spirit creature token.

Target opponent loses 2 life.
Inscribe {1}{B} ({1}{B}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Whenever another creature you control enters, you may gain 1 life.
Whenever a creature enters under an opponent's control, you may have that player lose 1 life.

When Hashiro's Vanguard enters, each player sacrifices a nontoken creature.

You may cast Heralds of Shikai from your graveyard as long as a creature an opponent controls died this turn.

When Keeper of Dark Shadows enters, if it's not a token, target opponent reveals their hand. You may choose a creature card from it. Create a token that's a copy of that card, except it's a colorless Spirit.

Sacrifice Kemono-no-Oni: Return target creature card from your graveyard to your hand.

Equipped creature gets +2/+2.
Whenever equipped creature attacks, you may return target creature card with mana value 2 or less from your graveyard to the battlefield.
Equip {2}

Art of war — At the beginning of your end step, if Kurayami Butcher dealt damage to an opponent, you may destroy target creature that was dealt damage this turn.

Whenever another nontoken creature you control dies, you may exile it. If you do, create a 2/2 colorless Spirit creature token.

Pay 3 life: Put a +1/+1 counter on target creature.

When Sasori Nightrunner enters, create a 2/2 colorless Spirit creature token.
Whenever a colorless creature you control dies, each opponent loses 1 life.

Destroy target creature. If an opponent lost life this turn, that creature's controller mills five cards.

Menace
Art of war — At the beginning of your end step, if Shikai Hunters dealt damage to an opponent this turn, put a +1/+1 counter on it.

Shikai Revenant enters tapped.
At the beginning of your end step, if an opponent lost life this turn, you may return Shikai Revenant from your graveyard to your hand.

Partner with Kasoha, Keeper of Truths (When this creature enters, target player may put Kasoha into their hand from their library, then shuffle.)
Whenever Shizura, Keeper of Traditions or another legendary creature dies, target player draws two cards and loses 2 life.

Return target creature card from your graveyard to your hand.
Inscribe {3}{B} ({3}{B}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Whenever you cast an instant or sorcery spell, target creature gets +1/+1 until end of turn.

{T}, Sacrifice an Equipment: Return target Equipment card from your graveyard to the battlefield. Activate only as a sorcery.

This spell can't be countered.
Firebloom deals 3 damage to target creature or planeswalker.

When Ikari-no-Oni enters, other creatures you control get +1/+0 until end of turn.

Art of war — At the beginning of your end step, if Jaakuna Betrayer dealt damage to an opponent this turn, you may discard a card. If you do, draw a card.

When Jaakuna Bloodsworn enters, any opponent may have it deal 3 damage to them. If a player does, sacrifice Jaakuna Bloodsworn.

Destroy target artifact.
Inscribe {2}{R} ({2}{R}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

As long as it's your turn, Kamito Champion has first strike.
Kamito Champion gets +1/+1 as long as it's equipped, enchanted, or has a card inscribed onto it.