msem-instigator

Until end of turn, target creature gets +2/+2 and gains “Whenever this creature attacks, you may post a bounty on target creature.” (Put a bounty counter on that creature. It has “When it dies, each opponent draws a card” as long as it has a bounty counter on it.)

Search your library for a card, put that card into your hand, then shuffle. If you control two or more creatures with -1/-1 counters on them, add {B}{B}{B}.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

Transcend (Activate as a sorcery to gain the next type and a +1/+1 counter.)
Flying
Tamaak the Arid Swarm can only transcend if you've sacrificed a permanent this turn.
{B}{G}: Demon — Create two 1/1 black Insect creature tokens with flying.
{X}{B}{G}: Elder — Destroy each other nonland, nontoken permanent with mana value X or less.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever another artifact or enchantment you control enters, add a quest counter.
1, 2 — You gain 3 life.
3 — Mill three cards, then return an artifact or enchantment card from your graveyard to the battlefield. Exile Seek the Maker's Egg.
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Create two 1/1 red and white Warrior creature tokens. Those tokens gain first strike until end of turn.

At the beginning of your first main phase, you may discard a card. If you do, draw a card and create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)
At the beginning of your end step, if Kessig Tombrobber didn't attack this turn, transform it.

Vigilance
Whenever Keeper of the Bloodline and at least two other creatures attack, creatures you control get +1/+1 until end of turn.

When Telarine Riftcrosser enters, create a 1/1 Scout creature token that's all colors.
Creature tokens you control have menace.

Whenever you gain life for the first time each turn, draw a card.
{3}{G}{W}: You gain life equal to the greatest toughness among creatures you control.

{2}, {T}, Sacrifice Char Brewer: Exile target instant or sorcery card from your graveyard. You may cast that card this turn.

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

Landfall — Whenever a land you control enters, you may reveal the top card of your library. If it's a land card, put it into your hand.

Lands target player controls don't untap during their controller's next untap step. Tap up to one target land that player controls.

{2}, {T}: You gain life equal to the number of colors among cards in your graveyard.
{W}{U}{B}{R}{G}: Transform Performer of Enlightenment.

Prevent all combat damage that would be dealt this turn.
Satrapycycling {2} ({2}, Discard this card: Search your library for a Satrapy card, reveal it, put it into your hand, then shuffle.)

Whenever you draw a card, you may have target player mill two cards.

Enchant creature
Enchanted creature gets +2/+0 and has first strike.

Flash
When Outland Alchemist enters, return another permanent you control to its owner's hand.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever Steelhoof Battlechief attacks, another target attacking creature you control gets +2/+2 and gains trample until end of turn.

Enchant non-Army creature
Enchanted creature can't attack or block.
When Banishment of Aspirations enters, amass Soldiers 1. (Put a +1/+1 counter on an Army you control. It's also a Soldier. If you don't control one, create an 0/0 black Soldier Army creature token first.)

This spell costs {2} less to cast if a permanent you controlled left the battlefield this turn.
Target creature gets +3/+0 and gains trample until end of turn.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Whenever you cast an enchantment, instant, or sorcery spell, Noble Barracuda gets +1/+0 until end of turn. Scry 1.

Menace
When Darna's Atrocity enters, you may pay 2 life. If you do, you draw two cards and mill two cards.
{B}, Exile a card from your graveyard: Darna's Atrocity gets +1/+1 until end of turn.

Menace (This creature can't be blocked except by two or more creatures.)