msem-instigator

When Calamity Rose enters, each player chooses a number of artifacts they control equal to the number of artifacts controlled by the player who controls the fewest, then sacrifices the rest. Players sacrifice creatures, enchantments, lands and planeswalkers the same way.

Target creature gets +3/+2 and gains menace until end of turn.
Quickdraw {1}{R} (When a creature you control blocks or becomes blocked, you may cast this spell for {1}{R}.)

Create two 1/1 green Elf Scout creature tokens. They gain reach until end of turn.

Search your library for a card and put it into your hand, then shuffle. You lose life equal to the number of cards in your hand.

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

As an additional cost to cast this spell, discard two cards.
Draw three cards.

Whenever a card is put into a graveyard from anywhere, put a +1/+1 counter on Chief Striking Dawn.
{1}{B}{G}, Remove three counters from Chief Striking Dawn: Return a permanent card from your graveyard to the battlefield.

Flash
When Collapsed Mine enters, exile another target nonland permanent until Collapsed Mine leaves the battlefield.

First strike
Whenever Creed, Eternal Straggler attacks, exile the top card of your library. You may play that card this turn, and that spell costs {2} less to cast.

Hexproof
Whenever one or more cards are put into your graveyard from anywhere, Creeping Hidebehind gets +1/+0 until end of turn.

Crossfire deals 1 damage to each creature.
Quickdraw {2}{R} (When a creature you control blocks or becomes blocked, you may cast this spell for {2}{R}.)

Reach
Scarecrow spells you cast cost {1} less to cast.

Whenever Daisite Express attacks, draw a card.
Whenever Daisite Express deals combat damage to a player, discard a card.

Dead Man's Hand enters tapped.
{T}, Sacrifice Dead Man's Hand, two permanents with mana value 1, and two permanents with mana value 8: Target player loses the game.

When Deputy Gibem enters, post a bounty on each creature and each planeswalker. (Put a bounty counter on those permanents. Each of them have “When this permanent dies, each opponent draws a card” as long as it has a bounty counter on it.)

{T}: Add one mana of any color.
When you tap Derelict Town for mana, return it to its owner's hand.

Defender
Whenever Derelict Watcher or another Scarecrow you control enters, create a 1/1 black Bird creature token with flying.

Exile the top two cards of your library. Until end of turn, you may play cards exiled this way. If an instant or sorcery spell cast this way would deal damage to a player or planeswalker, it deals double that damage instead.

{3}{W}{W}: Detain target nonland permanent. (Until your next turn, that permanent can't attack or block and its activated abilities can't be activated.)

Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)

Counter target instant spell.

This spell costs {2} less to cast if you control a Rogue.
Target opponent discards two cards.

Protection from Spirits
At the beginning of each end step, if a card was put into exile or a graveyard from anywhere this turn, draw a card.

When Drifting Warden enters, exile another target creature until Drifting Warden leaves the battlefield.
{3}{W}: Exile Drifting Warden. Return it to the battlefield under its owner's control at the beginning of the end step.

Menace, haste
Other Centaurs you control get +1/+0.