msem-instigator

Search your library for a card, put it into your hand, shuffle, then add three mana in any combination of colors.
{1}, Discard Tahli's Council: Add one mana of any color. Scry 1.

{X}{G}: Put X +1/+1 counters on target noncreature, nonplaneswalker permanent you control. It becomes an Elemental creature with base power and toughness 0/0 in addition to its other types. (This effect lasts indefinitely.)

When Essence of Nurture enters, put a +1/+1 counter on another target creature, then you gain life equal to that creature's toughness.

Trample
Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)
Whenever Rage-Fueled Adventurer attacks, you may have it fight target creature you don't control.

Menace
When Zygos's Decimators enters, put a number of +1/+1 counters on it equal to your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Exile any number of target creatures you control, then return those creatures to the battlefield under their owner's control.

Other Actors you control get +1/+1.
Whenever a permanent you control transforms, Lantern Tender deals 2 damage to any target and you gain 2 life.

At the beginning of your end step, if an opponent lost life this turn, Kogane the Crimson Consort deals 2 damage to each opponent and you gain 2 life.

Destroy target non-Xirix permanent. If that permanent had mana value 6 or greater, take an extra turn after this one.

As Damian, the Boss enters, pay up to 5 life. He enters with that many additional loyalty counters.
[–X]: You gain X plus 3 life.
[–1]: You draw a card and each opponent discards a card.
[–4]: Destroy up to one target creature. Create a 3/3 green Mole creature token.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
When Eager Hatchling has three or more +1/+1 counters on it, remove them all and transform it.

[+1]: Search your library for a land card, put it onto the battlefield, untap it, then shuffle. Sacrifice a land.
[–2]: Destroy target noncreature permanent. Its controller may search their library for a basic land card, put that card onto the battlefield, then shuffle.
[–6]: Return any number of land cards from your graveyard to the battlefield and untap them. They become 3/3 creatures with haste in addition to their other types.

Menace, lifelink
Whenever Jonah of the Spellbane deals combat damage to a player, destroy target creature or planeswalker, then scry 1.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
{1}{W}, Sacrifice a creature or enchantment: Scry 1, then draw a card. Activate only if Trauma Surgeon has a +1/+1 counter on it.

Exile target creature with mana value 2 or less.

Tap up to one target nonland permanent and put a stun counter on it.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

Whenever this creature enters or attacks, each player discards a card. If one or more land cards were discarded this way, this creature gains deathtouch until end of turn.
At the beginning of each opponent's end step, if that player didn't cast a spell this turn, that player loses 2 life and you gain 2 life.

Enchant creature
Enchanted creature can't be blocked.
{1}{G}: Enchanted creature gets +1/+1 and gains hexproof until end of turn.

{2}, Exile a land card from your graveyard: Create a token that's a copy of that land.

Destroy up to X target artifacts and/or enchantments. If X is 3 or more, you gain twice X life. If X is 6 or more, create two X/X Elemental creature tokens that are all colors.

Enchant creature
Spirited (When this enters, you may activate one of its activated abilities without paying its cost.)
{1}: Enchanted creature can't attack or block this turn.

{T}: Add {C}.
{1}, {T}: Add two mana of different colors. Activate only if you control five or more lands.

Equipped creature is a Dragon and has base power and toughness 4/4, flying, and “{2}: This creature gets +1/+0 until end of turn.”
Equip {3}

Lifelink
When Runic Soulthief enters, target player loses X life and you gain X life, where X is the number of enchantments you control.

As an additional cost to cast this spell, reveal a sorcery card from your hand or pay {2}.
Return target card from your graveyard to your hand.