msem-instigator

The second spell you cast each turn costs {2} less to cast.
Whenever you cast a spell, each opponent loses 1 life and you gain 1 life.

Creature tokens you control get +1/+1 and can block an additional creature each combat.

You may have Reaping Willow assign its combat damage as though it weren't blocked.
{2}{G}: Reaping Willow gains indestructible until end of turn.

Flying, lifelink
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever Recreator of Myths attacks, you may cast target instant or sorcery spell from your graveyard. If you do, exile that card instead of putting it into your graveyard as it resolves.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
As long as you control three or more artifacts, Regal Seasnake has vigilance. (Attacking doesn't cause it to tap.)

When Reha, Entropy's Call enters, you may search your library for any number of land cards with different names and exile them with harvest counters, then shuffle.
At the beginning of your upkeep, you may put a card that you own in exile with a harvest counter on it at random onto the battlefield tapped.

If one or more -1/-1 counters would be put on a creature an opponent controls, put twice that many -1/-1 counters on it instead.

Reinbreaker Behemoth attacks each combat if able.

Vigilance
Disgraced 1 (This enters with a -1/-1 counter. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)

When Renegade Servitor enters, you gain 2 life and scry 1.

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
When Renegade Spiritualist becomes renowned, create a 1/1 green Spirit creature token.

When Repurposed Custodian enters, shuffle any number of target cards from graveyards into their owner's libraries.

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

Deploy 4 (As this enters, you may tap any number of other creatures you control with total power 4 or more.)
When Revolutionary Recruiters enters deployed, gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.

Flying
Rezzal, the Loamfeaster gets +1/+1 for each nonland card exiled with it.
You may play lands exiled with Rezzal.
{1}{B/G}: Exile target card from an opponent's graveyard. Activate only outside of combat.

First strike, lifelink
Tribute 4 (As this creature enters, an opponent of your choice may put four +1/+1 counters on it.)
When Righteous Priestess enters, if tribute wasn't paid, the chosen player can't cast creature spells during their next two turns.

This spell costs {1} less to cast for each instant and/or sorcery card in your graveyard.
Once each turn, when you cast an instant or sorcery spell, you may create a 4/4 white Angel Cleric creature token with flying and vigilance.

Concord — When Riptide Mystic enters, if there are four or more card types among permanents you control, you may return target nonland permanent to its owner's hand.

Whenever Roaring Illusion attacks alone, for each other creature you control, create a token that's a copy of that creature and that's tapped and attacking. Exile those tokens at the beginning of the next end step.

If a creature an opponent controls would die, exile it instead.
Whenever Rocket Poacher deals combat damage to a player, put a card exiled with it onto the battlefield under your control.

Trample
Tribute 3 (As this creature enters, an opponent of your choice may put three +1/+1 counters on it.)
When Rockpounding Saurian enters, if tribute wasn't paid, you may destroy up to one target artifact, up to one target land and up to one target Fortress.

Whenever you cast a modal instant or sorcery spell, draw a card.
{W}{U}{B}{R}{G}: Copy target modal instant or sorcery spell. You may reselect modes and choose new targets for the copy, and you may choose an additional two modes and may choose the same modes more than once.

At the beginning of your upkeep, look at the top card of your library. If its mana value is less than or equal to the number of Scouts you control, you may reveal it and draw a card.

Flying
When Rooftop Robber enters, another target Pirate or Rogue you control gets +2/+0 and can't be blocked this turn.