msem-instigator

Source Decay deals 2 damage to each opponent. Create two 1/1 colorless Servo artifact creature tokens.
Whenever a creature you control deals combat damage to a player, you may pay {2}{B}{R} and sacrifice it. If you do, return Source Decay from your graveyard to your hand.

Trample
Whenever a creature dealt damage by Sovereign of Old Lovi this turn dies, put a +1/+1 counter on Sovereign of Old Lovi.

All creatures get -2/-2 until end of turn. At the beginning of the next end step, if three or more creatures died this turn, create two tapped Treasure tokens.

Whenever a land you control enters, you gain 1 life.
{3}{G}, Sacrifice Sower of Spring: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Whenever Sower of Virulent Thoughts attacks, you may return a creature you control to its owner's hand. If you do, put a +1/+1 counter on target creature you control.

Exile target creature. That creature's controller reveals cards from the top of their library until they reveal a creature card. That player puts that card onto the battlefield, then shuffles the rest into their library.

Menace
When Spaceship Invader enters, destroy target creature you don't control with mana value 3 or less.

Destroy each creature with power 3 or greater.

Exile the top card of your library. You may have Spark Inspiration deal 2 damage to each opponent. If you don't, you may play that card until end of turn.

Primal {2}{R} (During your turn, you may cast this spell for {2}{R} instead of playing a land.)
Target creature gets +2/+0 and gains double strike until end of turn.

Sparring Ground enters with a +1/+1 counter on it.
{T}: Add {C}.
Whenever a creature you control enters, you may move a +1/+1 counter from Sparring Ground onto that creature.

Flying, haste
Whenever Spawn of Hadak attacks, draw a card, then discard a card.

Trample
When Spawn of Qiyan enters, distribute four +1/+1 counters among any number of target creatures you control.
{2}{G}: Put Spawn of Qiyan from your graveyard into your library second from the top.

Menace
Whenever you cast a cryptic spell, you may return target creature card from your graveyard to your hand. (Artifacts, enchantments and modal spells are cryptic.)

When Speaker of Open Waters enters, create a green and white Aura enchantment token named Moray's Resolve attached to target creature you control. The token has enchant creature and “Enchanted creatures you control get +2/+2 and have trample and lifelink.”

Colorless creatures you control have “{T}: Add {C}.”

When you cast this spell, create a token that's a copy of it.
Equipped creature gets +2/+2.
Equip {2}

Vigilance
When Spear of the Folded Fan enters, if you control a legendary creature, you gain 4 life.

Spearhead deals X damage to target player. (Then exile this card. You may cast the creature later from exile.)

Whenever you cast a noncreature spell, create a 1/1 colorless Servo artifact creature token.
{1}{U}, {T}, Exile three noncreature cards from your graveyard: Draw a card.

Whenever an artifact you control enters, you may put a progress counter on Spectacle of Innovation.
[progress 1+] Artifact creatures you control get +1/+1.
[progress 3+] Artifact creatures you control have flying and hexproof.
Artifact creatures you control have flying and hexproof.

Vision (Whenever this or another creature you control enters, reveal the top card of your library. Then you may put that card into your graveyard.)
Whenever Spectral Hunter envisions a creature card, creatures you control get +1/+0 until end of turn.

Put target creature on top of its owner's library.
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.)

Prowess
Whenever you cast a noncreature spell, you may pay {R}. If you do, post a bounty on target creature. (Put a bounty counter on that creature. It has “When this creature dies, each opponent draws a card” as long as it has a bounty counter on it.)

As an additional cost to cast this spell, exile X cards from your graveyard.
Choose one —
• Target player mills X cards.
• Look at the top X cards of your library. Put one into your hand, and the rest on the bottom of your library in any order.