msem-instigator

Whenever you cast a nonblue spell, create a 1/0 blue Horse Nymph creature token.
Horses get +1/+1 and have flying.

Primal {R} (During your turn, you may cast this spell for {R} instead of playing a land.)
Target creature gets +4/+0 and gains trample until end of turn.

This spell costs {2} less to cast and may be cast as though it had flash if an opponent searched their library this turn.
When Ridge Warden enters, exile another target nonland permanent with mana value 4 or less until Ridge Warden leaves the battlefield.

Other Humans you control get +1/+1.
Whenever Righteous Chaplain or another Human you control enters, tap target creature an opponent controls.

Whenever another creature you control enters, put a +1/+1 counter on it.
Whenever Rilken Preserver attacks, you may exile target nonland permanent you control, then return it to the battlefield under your control.

Destroy target creature. Its controller loses 1 life.

You can't draw cards.
{2}{R}: Exile the top card of your library. You may play it this turn.

Trample
Risti Assault Squadron can't attack unless all other creatures you control also attack. (It can attack if it's the only creature you control.)

At the beginning of your upkeep, you lose 1 life, then investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
Whenever you sacrifice a permanent, each opponent loses 1 life.

As Ritual Preparations enters, choose a color.
You don't lose unspent mana of the chosen color as steps and phases end.

Bloodprice {2}{B} (You may cast this card by sacrificing a creature and paying its bloodprice.)
Create X 2/2 black Demon creature tokens, where X is one plus the number of creatures that died this turn.

Destroy all creatures with mana value 3 or less.

Choose one or both —
• Riverboat Assault deals 3 damage to target creature.
• Target creature gets +3/+3 until end of turn.

{U}, {T}: You may tap or untap another target creature.
Whenever one or more other creatures you control deal combat damage to a player, you may untap Riverchase Diver.

Harmony — Untap target permanent.
Whenever you cast an instant or sorcery spell, harmonize. (Trigger up to one harmony of one permanent you control.)

As Road to Alratha enters, choose near or far.
Whenever you attack,
• Near — Creatures you control get +1/+1 until end of turn.
• Far — Put a +1/+1 counter on target creature you control. Untap it.

Search your library for up to three basic land cards, reveal those cards, shuffle, then put one of them into the battlefield tapped, one into your hand and one on top of your library.

Search your library for up to two basic land cards and put them onto the battlefield tapped, then shuffle.
Fuse (You may cast one or both halves of this card from your hand.)

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.

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature deals combat damage to a player, you may aetherize it. (To aetherize, create a token that's a copy of it, then exile that token.)

Choose three. You may choose the same mode more than once.
• Return target creature with mana value 2 or less to its owner's hand.
• Scry 1, then draw a card, then discard a card.
• Target creature gets -2/-0 until end of turn and attacks this turn if able.

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.

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

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.

(Activate each submodule once as a sorcery. When this enters, activate one submodule for free.)
{G}{G}{G}: Seed
Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.
{G}{G}{G}: Soil
Destroy target noncreature permanent.
{G}{G}{G}: Stem
Root Module gains “You may play an additional land on each of your turns.” and “Lands you control are every basic land type in addition to their other types.”