msem-instigator

(Add a quest counter as this enters. Sacrifice after 4.)
Whenever a creature you control enters, add a quest counter.
1 — Exile target nonland permanent an opponent controls until target creature you control leaves the battlefield.
2, 3 — Each player may scry 1.
4 — Put all cards exiled with Bind the Great Evil into their owners' graveyards.

When Bind the Mind enters, each poisoned opponent reveals their hand. Then choose a nonland card name.
Spells with the chosen name can't be cast.

Enchant creature
Enchanted creature can't attack or block alone.

Equipped creature gets +1/+1.
Whenever equipped creature becomes blocked, you may pay {1}{W}. If you do, detain each creature blocking it. (Until your next turn, those creatures can't attack or block and its activated abilities can't be activated.)
Equip {2}

Flash
When Binding Stones enters, exile target creature with power 3 or less until Binding Stones leaves the battlefield.

When Bio-Sequencer enters, conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)
{1}, {T}, Sacrifice Bio-Sequencer: Add one mana of any color.

Put a +1/+1 counter on each of up to X target creatures.
Augmented — If you've spent {W}{U}{B}{R}{G} to cast spells this turn, instead put three +1/+1 counters on each of those creatures. They gain trample until end of turn.

{T}: Add one mana of any color a basic land you control could produce.

Enchant creature
Enchanted creature gets +2/+2 and has lifelink.

When Biohazard enters, destroy all other nonland permanents with mana value X or less.
At the beginning of each end step, each opponent loses life equal to the number of cards they've drawn this turn plus the number of spells they've cast this turn.

Return up to one target spell to its owner's hand.
Create two 1/1 blue Elemental creature tokens with flying. They can't block this turn.

When Bioluminescent Predator dies, draw a card, then you may put a land card from your hand onto the battlefield.

When Bird Call enters, search your library for a creature card, reveal it, shuffle, then put that card on top.
{2}, {T}: Target creature gets +1/+1 until end of turn.

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.

Flying
Bird of Many Feathers can block only creatures with flying.
Whenever you scry, put a +1/+1 counter on Bird of Many Feathers.

Create a 1/1 blue Bird creature token with flying, then put the bottom card of your library into your hand.

Exchange control of two target permanents that share a permanent type.
Lifecycle {3} ({3}, Discard this card: Create two tapped 1/1 colorless Elemental creature tokens.)

All creatures get -4/-4 until end of turn.

Whenever a creature card is put into your graveyard from the battlefield, exile it. You lose life equal to that card's mana value. Put it onto the battlefield tapped at the beginning of your next upkeep.

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
Return target creature card from your graveyard to the battlefield. If it was put there from the battlefield this turn, create a token that's a copy of it. If you're in a renaissance, create a token that's a copy of it.

Whenever Birthing Elemental or another nontoken creature you control dies, create a 1/1 green Saproling creature token.

Lifelink
When Birthright Proselyte enters, return target permanent card with mana value 2 or less from your graveyard to the battlefield.

Menace
When Bit Player dies, it deals 1 damage to each opponent.

Destroy target creature with flying.

Flying
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)
When Bitter Corvus enters, you may reveal the top X cards of your library, where X is Bitter Corvus' power. You may put up to one card revealed this way into your hand. You lose life equal to its mana value. Put the rest into your graveyard.