msem-instigator

Flying
Whenever Avengeance Angel attacks, you may put a creature card with mana value 2 or less from your hand or graveyard onto the battlefield.

Trample
Whenever a player casts a noncreature spell, that player sacrifices a noncreature permanent.

Create a 5/3 black Horror creature token.
Flashback {1}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

(Add a quest counter as this enters. Sacrifice after 6.)
Whenever you cast an instant or sorcery spell from your hand, add a quest counter.
2, 3, 4, 5 — Exile target instant or sorcery spell you control instead of putting it into your graveyard as it resolves. You may cast that card from exile until Awaken the SOURCE leaves the battlefield.
6 — Exile target instant or sorcery spell you control as it resolves. Until end of turn, you may cast cards exiled with Awaken the SOURCE without paying their mana costs.
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Pressure {3}{B}{B} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Each player sacrifices a creature. Put a creature card from a graveyard onto the battlefield under your control.

Enchant creature
When Awash in Despair enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Ayala, Shrouded Shepherd can't attack or block unless your life total is greater than or equal to your starting life total.
Lifelink, indestructible
Whenever a creature attacks you or a planeswalker you control, you may pay {2}. If you do, create a 1/1 white Spirit creature token with lifelink blocking that creature.

Azos's Fury deals 6 damage to target creature or planeswalker you don't control. When excess damage is dealt this way, choose one —
• Add that much {R}.
• Azos's Fury deals that much damage to that permanent's controller.

Draw X cards, where X is the number of differently named lands you control.

Basic Forests you control have “{G}, {T}: Untap target attacking creature and remove it from combat.”

Scry X, then purge X times. You lose X life. (To purge, exile two cards that share a type from graveyards. If you do, draw a card.)

When Bal's Descent enters the battlefield, each player sacrifices a creature, discards two cards, and mills three cards.
{1}{B}{B}: Transform Bal's Descent. Activate only if your fealty to Swamps is five or greater. (Each Swamp you control counts towards your fealty to Swamps.)

This spell costs {U} less to cast if you dealt combat damage to a player this turn with a Rogue.
Flying
When Balloon Voyager enters the battlefield, draw a card.

Ward {3} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)
Lifecycle {3} ({3}, Discard this card: Create two tapped 1/1 colorless Elemental creature tokens.)

As an additional cost to cast this spell, sacrifice a creature.
All creatures get -X/-X until end of turn, where X is the sacrificed creature's power.

When Baneblade Stalker enters the battlefield, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

Exile target creature or planeswalker and all other creatures its controller controls with the same name as that permanent. Search its controller's graveyard, hand, and library for any number of nonland cards with the same name as that permanent and exile them. Then that player shuffles.

Destroy all creatures. Exile all graveyards.

Trample
When Bank Skimmer enters the battlefield, create a green Aura enchantment token named Turtle's Valor attached to target creature. The token has enchant creature and “Enchanted creature gets +X/+X, where X is its mana value.”

Other Warriors you control have first strike.
Other Barbarians you control get +1/+0.

First strike (This creature deals combat damage before creatures without first strike.)
Other Soldier creatures you control get +1/+1 and have first strike.
{3}{W}: Create a 1/1 white Soldier creature token.

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Whenever Barrow Banshee deals combat damage to an opponent, that player discards a card at random.

Flying, first strike, vigilance, lifelink
When Bastion Valkyrie dies, create three Function tokens with “Choose a creature targeted by this spell. It gains flying, first strike, vigilance, and lifelink until end of turn.” (They're enchantments. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

When Bastion Warden enters the battlefield, exile target creature an opponent control until target enchantment you control leaves the battlefield.

Renown 2 (When this creature deals combat damage to a player, if it isn't renowned, put two +1/+1 counters on it and it becomes renowned.)
Whenever a creature you control becomes renowned, draw a card.