msem-instigator

Enchant creature
Enchanted creature gets +1/+1 for each artifact and/or enchantment you control.

Puzzlebox (Begin the game with this and another card you own from outside the game in the command zone, locked. That card is face down until you unlock this.)
{3}: Unlock Mortal's Conundrum. If the revealed card is black, put it into your hand. Otherwise, put it on top of your library.
At the beginning of your upkeep, if Mortal's Conundrum is unlocked, you lose 2 life.

Choose one —
• Return all tapped creatures to their owners' hands.
• Return all untapped creatures to their owners' hands.

When Terraformer's Globe enters, draw a card.
{T}: Target land you control becomes the basic land type of your choice until end of turn.

Whenever you cast a spell from anywhere other than your hand, surveil 1.

{T}, Pay 1 life: Add {G}.
{8}{G}, Exile Singers' Grove from your hand: Creatures you control get +7/+7 until end of turn.

Choose one. If you control four or more creatures, you may choose any number instead.
• Exile target artifact or enchantment.
• Exile target player's graveyard. Stand as One deals 1 damage to each opponent for each card type among cards exiled this way.
• Target creature you control deals damage equal to its power to target creature or planeswalker.

Sacrifice another creature: Grisly Rougarou deals damage equal to the sacrificed creature's power to any target.

Gestalt (When this or another creature enters under your control, you may merge it with the one in play, keeping counters and attachments. They become the permanent on top plus all abilities from under it.)
Whenever this creature attacks, if it's merged with another card or token, it deals 2 damage to target player or planeswalker.

Target creature gets +1/+0 and gains vigilance and lifelink until end of turn.

For each color of mana spent to cast this spell, create a 0/2 green Egg creature token. (Then exile this card. You may cast the creature later from exile.)

Whenever another creature enters, you gain 1 life.

Indestructible
As long as your devotion to green is less than five, Nylea isn't a creature.
Whenever another creature you control deals combat damage to a player, draw a card.
{1}{G}: Until end of turn, another target creature you control gains haste and can't be blocked by creatures with power 3 or less.

Enchant creature
Enchanted creature and all other creatures with the same name as that creature can't attack or block.

Lifelink
Vitality of Blossoms has indestructible as long as your life total is greater than your starting life total.

Gain control of target creature with mana value 4 or less until end of turn. Untap that creature. It gains haste until end of turn.

Reveal the top five cards of your library. An opponent separates those cards into two piles. Exile one of those piles. Until the end of your next turn, you may play those cards. Shuffle the other pile into your library.

Flying
Starbane Elemental's power and toughness are each equal to the number of creatures with flying you control.
When Starbane Elemental enters, destroy all creatures without flying.

You may exchange a creature you both own and control with a creature card in your hand that has the same mana value.
Flashback {1}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Lifelink
At the beginning of your end step, if you've gained 3 or more life this turn, create a 2/2 white Bird creature token with flying.

Bigroot Valley enters tapped.
{T}: Add {R} or {G}.
{1}, {T}: Add one mana of any color.

Choose two —
• Exile target spell.
• Target player may scry 2. If they do, they draw a card.
• Return target artifact card from your graveyard to the battlefield.
• Destroy target nonartifact creature.

({T}: Add {U} or {R}.)
Frostfire Geysers enters tapped unless you control a basic Island or a basic Mountain.

Wu Xing (Add effects based on the number of colors of mana spent to cast this spell.)
1 | Target creature's owner puts it on the top or bottom of their library.
3 | Return a creature card from your graveyard to your hand.

Trample
Disgraced 2 (This enters with two -1/-1 counters. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)
Whenever a creature an opponent controls blocks, Master of No Quarter deals 2 damage to that creature.