msem-instigator

Flying, haste
Whenever you attack with three or more creatures, harmonize three times. (To harmonize, trigger up to one harmony of a permanent you control.)
If you would harmonize, you may instead return Herald of Festivities from your graveyard to your hand.

Attacking creatures get +2/+0 and gain trample until end of turn.

Menace
Lonely Devil can't attack or block alone.

Exile the top three cards of your library. For each land card exiled this way, create a colorless artifact token named Lotus Petal with “{T}, Sacrifice this artifact: Add one mana of any color.” Until the end of your next turn, you may cast nonland cards exiled this way.

Add three mana of any one color.

At the beginning of combat on your turn, create a 1/1 red Cleric creature token with haste.
At the beginning of your end step, sacrifice each Cleric token you control unless you've cast an instant or sorcery spell this turn.

Flying
Creatures you don't control have “{T}: This creature fights Ontarachie Apex. Activate only as a sorcery.”

Tithe (As you cast this spell, you may tap three artifacts and/or creatures you control.)
Create two 1/1 red Cleric creature tokens with haste. If this spell's tithe was paid, create four of those tokens instead.

Harmony — Pyrodancer deals 1 damage to each opponent.
When Pyrodancer enters, harmonize. (Trigger up to one harmony of one permanent you control.)

As long as it's your turn, Rallying Rector has first strike.
Whenever Rallying Rector attacks, you may discard a card. If you do, search your library for a card named Rallying Rector, reveal it, put it into your hand, then shuffle.

{2}{R}: Target creature can't block this turn.

Shock and Awe deals 2 damage to target creature. Creatures can't block this turn.

Destroy target artifact or nonbasic land. Its controller creates a colorless artifact token named Lotus Petal with “{T}, Sacrifice this artifact: Add one mana of any color.”

Harmony — Target creature gains haste until end of turn.
When Streetside Entertainer enters, harmonize. (Trigger up to one harmony of one permanent you control.)

Tithe (As you cast this spell, you may tap three artifacts and/or creatures you control.)
You may cast this spell as though it had flash if its tithe is paid.
Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.

Harmony — Creatures you control gain double strike until end of turn.
When Twirling Duet enters, harmonize. (Trigger up to one harmony of one permanent you control.)

Target creature you control gains trample until end of turn. Whenever that creature deals damage to a player this turn, create a colorless artifact token named Lotus Petal with “{T}, Sacrifice this artifact: Add one mana of any color.”

Whenever Zealous Scaleblight becomes tapped, it deals 1 damage to any target.

Trample
As long as it's an opponent's turn, Ambushing Alligator is a blue Bird with base power and toughness 1/1 and has flying and hexproof.

Destroy target artifact or enchantment. Scry 2.

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Destroy target creature with flying.

Reach
{1}{B}: Bloomcrawler gains deathtouch until end of turn.

Target creature gets +4/+4 until end of turn. Create a colorless artifact token named Lotus Petal with “{T}, Sacrifice this artifact: Add one mana of any color.”