msem-instigator

Whenever a creature dealt damage by Rei's Betrayer this turn dies, you gain life equal to that creature's toughness.

Rei, the Supplanter gets +1/+1 for each Forest you control.
At the beginning of each player's end step, if that player didn't play a land this turn, create a Forest token.

Whenever a creature you control perseveres this turn, you gain 3 life. (A creature perseveres when it survives damage.)

Glitch {2} (Remove one [restriction] for each time you pay the glitch cost.)
Destroy target artifact or enchantment [with mana value 3 or less].

[+1]: Create a 1/1 blue Elemental creature token with flying, then crystallize twice. (Put a +1/+1 counter on a creature you control or create a Treasure.)
[–3]: Exile target nonland permanent. As long as it's exiled, its owner may pay {W}{U}{B}{R}{G} as a sorcery to put it into their hand.
[–7]: You get an emblem with “Pay 1 life: Add one mana of any color.” Then you gain 100 life.

{T}: Target player exiles a card from their graveyard.
{2}, Sacrifice Remnant of Past Realities: Exile each opponent's graveyard. Draw a card.

Rend deals 1 damage to any target and you gain 1 life.
Whenever you cast a black spell, you may pay {1} and exile Rend from your graveyard. If you do, destroy target creature or planeswalker if it was dealt damage this turn.

Whenever a creature enters, each opponent loses 1 life.

{T}, Sacrifice Renewal Grove: Search your library for a basic land card, put it onto the battlefield, then shuffle. If Renewal Grove entered since your last upkeep, that land doesn't untap during your next untap step.

Whenever another creature you control is dealt damage, put a +1/+1 counter on it. If you do, upgrade Renowned Healer. (Give it one of the listed counters it doesn't already have. The damaged creature must survive to get the counter.)
• +1/+1
• Flying
• Lifelink

Whenever a creature dies, put a +1/+1 counter on Repository of Thoughts.
At the beginning of each combat, you may move a counter from Repository of Thoughts to target creature.

Repurposed Construct enters tapped.
{T}: Add {B} or {G}.
{B}{G}, {T}, Sacrifice Repurposed Construct: Conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)

Sacrifice Repurposed Killdrone: It deals 1 damage to any target. You gain 1 life.

{2}, Sacrifice Research Aquarium: Draw a card.
When Research Aquarium is put into a graveyard from the battlefield, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

{1}: Exile target card from a graveyard.
At the beginning of combat on your turn, if there are three or more card types among cards exiled with Respectful Tracker, put a +1/+1 counter on target creature you control.

({T}: Add {G} or {W}.)
Whenever Resplendent Substratum becomes tapped, you lose 1 life unless you control two or more basic lands.

{W}, {T}: Tap target creature.

Enchant creature
Enchanted creature gets +2/+2 and attacks each turn if able.

Restored Automaton enters with X +1/+1 counters on it.
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

(Transforms from Ruined Theater.)
{T}: Add one mana of any color.

{T}: Add {C}.
{3}, Exile Resurgent Oasis from your graveyard: Choose a basic land type. Create a tapped colorless land token that's a Desert and the chosen basic land type.

Target opponent chooses a creature card in your graveyard. Return the chosen card from your graveyard to your hand.

[+2]: Each player sacrifices a creature. Then each player who did creates a 1/1 white and black Spirit enchantment creature token.
[–X]: You may put an enchantment card with mana value X or less from your hand onto the battlefield.
[–6]: Shuffle, then reveal the top seven cards of your library. Put any number of enchantment cards from among them onto the battlefield. Shuffle the rest into your library.

Archive 3 (As this enters, shuffle the top three cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
Whenever you draw a card from the archived library, put the top card of your main library on the bottom of the archived library.
{U}: Exchange a card from the archived library with a card from your hand.

Enchant creature
As long as enchanted creature has toughness 3 or less, it can't attack or block.