msem-instigator

Flying
Unveil {3}{W}{U} ({3}{W}{U}: Transform this. Unveil only as a sorcery.)

Enchant player
Death knell — Enchanted player loses 1 life and you gain 1 life. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)
Whenever a creature you control dies, enchanted player chooses a death knell ability of a permanent you control. Trigger that ability.

Equipped creature gets +1/+0 and has wither. (It deals damage to creatures in the form of -1/-1 counters.)
Equip {2}

Lifelink
Death knell — You gain 1 life for each permanent with a death knell you control. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)

Menace
Death knell — Put a +1/+1 counter on Guiltless Wraith. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)

Equipped creature has menace.
Whenever equipped creature attacks, it gets +X/-X until end of turn, where X is a number of your choice less than its toughness.
Equip {2}

Whenever you make first contact, create a Treasure token. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)
{T}, Return an artifact with mana value X you control to its owner's hand: You may cast a spell with mana value X plus 1 or less and with a different name from your hand without paying its mana cost.

Whenever Haunted Prodigy attacks, you may tap target creature.
Unveil {2}{W}{U} ({2}{W}{U}: Transform this. Unveil only as a sorcery.)

Whenever Haunting Maestro attacks, you may tap or untap up to two target creatures.

Wither (This deals damage to creatures in the form of -1/-1 counters.)
{X}{R}: Hearth Dweller gets +X/+0 until end of turn.

Whenever Herald of Purity is dealt damage, it deals that much damage to any target.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Whenever another nontoken creature you control dies, create a 1/1 green Saproling creature token.
{B}{G}, {T}, Sacrifice a creature: Return target permanent card from your graveyard to your hand.

Lifelink
When Herald of Royalty enters, creatures you control get +1/+1 and gain vigilance until end of turn.

Target opponent may draw two cards. If they do, you draw four cards. Otherwise, you create four 1/1 red Elemental creature tokens.

When Historiamancer enters, return target instant or sorcery card from your graveyard to your hand.

Choose three. You may choose the same mode more than once.
• You draw a card and you lose 1 life.
• Target opponent discards a card and loses 1 life.

Create X 1/1 blue Boar Dragon creature tokens with flying. (Then exile this card. You may cast the creature later from exile.)

This spell costs {3} less to cast if a permanent you controlled advanced this turn.
Gain control of target creature until end of turn. Untap it. It gains haste until end of turn.

Whenever you make first contact, Hotshot Renegade deals 2 damage to up to one target creature or planeswalker. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)

Choose one —
• Exile target artifact.
• Target player exiles two artifacts they control with mana value 0.

Advance {2}{W} (Cast this for {2}{W} to advance it as it enters. {2}{W}: Advance this as a sorcery.)
Whenever Hoverstepper advances, target creature gets +1/+1 and gains flying until end of turn.

Advance {3}{W} (Cast this for {3}{W} to advance it as it enters. {3}{W}: Advance this as a sorcery.)
Whenever Hrexa Enforcer advances, put a +1/+1 counter on it.

When Humble Tamer enters, create a 1/1 white Griffin creature token with flying.

Enchant player
For each 1 life enchanted player would gain, you gain 1 life instead unless that player pays {1}.

First strike
When Hunted Haunt dies, create a 1/1 black Scout creature token.