msem-instigator

{T}, Pay 1 life: Add {W} or {B}.
{2}, {T}, Sacrifice Royal Hospital and another permanent: Draw a card. Activate only during your turn.

Cesspool Scrapper can't block.
{5}{U}, Exile Cesspool Scrapper from your graveyard: Draw two cards.

Improve {1}{W} ({1}{W}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Knights you control have double strike as long as they're attacking.

Lifelink
Vanishing 1 (This creature enters with a time counter on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Whenever another creature you control dies, put a time counter on Dulling Necromancer.

Vigilance
When Paired Pathfinders enters, if three or more colors were spent to cast it, create a 1/1 colorless Servo artifact creature token.

Flying
Tawny Prophet enters with three +1/+1 counters on it.
{W/U}, Remove a +1/+1 counter from Tawny Prophet: Scry 1, then draw a card.

{2}{W}: Reappropriate. When you do, choose X, where X is one plus the number of artifact and/or enchantment cards exiled this way. You may choose the same mode more than once. (To reappropriate, exile exactly two cards from your hand and/or graveyard.)
• Exile target creature you own. At the beginning of the next end step, return that card to the battlefield under your control.
• Scry 2.
• Gain 3 life.

Trample
Whenever you attack, target creature gains first strike until end of turn. If you control a Dwarf and an Elf, that creature gains double strike until end of turn instead.

As Legacy Foundations enters, you may reveal a Plains or Swamp card from your hand. If you don't, Legacy Foundations enters tapped.
{T}: Add {W} or {B}.

Target creature you control gets +1/+1 and gains lifelink until end of turn. It fights target creature you don't control.

At the beginning of your end step, you may discard a creature card. If you do, you draw a card and you lose 1 life.
Whenever a creature you control attacks alone, you may cast a creature card from your graveyard. That creature enters tapped and attacking. If you do, sacrifice the creature you attacked with at end of combat.

When Suburban Farmer enters, you may search your library for a basic Plains card, reveal it, put it into your hand, then shuffle.
When Suburban Farmer dies, you gain 3 life.

Alpha (You may have this creature enter with a +1/+1 counter on it. If you do, it becomes alpha and can only attack alone.)
Lifelink

Prevent all combat damage that would be dealt this turn by each creature without a counter on it.

Lifelink
Whenever another creature you control with a counter on it dies, return it to its owner's hand. If that creature was an Avatar, return it to the battlefield under your control instead.

Reach
Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Other Elementals you control get +1/+1 as long as Miroran Skycatcher has a +1/+1 counter on it.

Whenever Ivory Curtain Producer attacks, if it's enchanted or you cast a spell that targeted it this turn, create a 1/1 colorless Construct Actor creature token.

This spell costs {2} less to cast as long as you've sacrificed an Idol this turn.

Whenever you cast a noncreature spell, Dynamic Wyvern gains flying until end of turn.

When Helicos Octopus enters, scry 1. If an opponent is cursed, scry 3 instead.

When Dominate the Desert enters, create a 3/3 green Elephant creature token with trample.
Whenever a creature you control assaults, you may return Dominate the Desert to its owner's hand.

Creature cards can't leave the graveyard or exile.
Players can't cast spells from graveyards or from exile.

When you unveil Tempest Termagant, you may put target land on top of its owner's library.

Archive 2 (As this enters, shuffle the top two cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
{R}{W}: Put a nontoken artifact or creature you own on the bottom of the archived library. Create a token that's a copy of it.

When Sentient Contraption enters, create a 1/1 colorless Thopter artifact creature token with flying.