msem-instigator

Flying
Whenever you cast a creature spell, if Script Spirit is in your graveyard, you may have it become a copy of that spell until end of turn.

Create two 1/1 white Human creature tokens.
Put a vigilance counter on target creature you control. It becomes a legendary God in addition to its other types.
Exile target creature an opponent controls that's a God or that has power 4 or greater.

This spell can't be countered.
Draw a card.
Reprise {2}{U} (As you cast an instant or sorcery spell, you may exile one card with reprise from your graveyard and pay its reprise cost. If you do, add its effects to that spell.)

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever a land you control enters, add a quest counter.
Create a 1/1 Scout creature token that's all colors.
Creatures you control get +2/+1 until end of turn.
Creatures you control get +1/+1 until end of turn.

Glorious end — When Seeker of Conto Sika dies, if it was tapped, draw a card.

Mill five cards, then you may exile any number of cards from your graveyard. Create an X/X black Horror creature token with menace, where X is the number of cards exiled in this way. (To mill five cards, put five cards from the top of your library into your graveyard.)

When Shaman of Burning Ashes enters, return target instant or sorcery card from your graveyard to your hand. When you do, each opponent loses X life, where X is that card's mana value.

Concord — {T}: Tap target nonland permanent. Activate only if there are four or more card types among permanents you control.

Kicker—Return a creature you control to its owner's hand. (You may return a creature you control to its owner's hand in addition to any other costs as you cast this spell.)
Counter target spell. If Shinrei's Ruse was kicked, draw a card.

{T}: Add {C}.
Shrine of the World-Shepherd's power and toughness are each equal to the number of differently named lands you control.
{3}{G}: Shrine of the World-Shepherd becomes a Beast creature in addition to its other types until end of turn.

Flash
Harmony — Another target creature gets +1/+0 and gains indestructible until end of turn.
When Siamang Tale-Singer enters, harmonize. (Trigger up to one harmony of a permanent you control.)

When Sihari's Groundblazer enters, create a red Aura enchantment token named Searing Crags attached to target land. The token has enchant land, “Enchanted land's name is Charred Causeway” and “Enchanted land has {T}: This land deals 1 damage to each opponent.”

You may look at the top card of your library any time, and you may play Deserts from the top of your library.
[+1]: You gain 1 life. You may discard a card. If you do, draw a card.
[–2]: Sihari deals 2 damage to any target. You may play an additional land this turn.
[–4]: Create an X/X red and green Sand Elemental creature token with trample and haste, where X is the number of lands you control.

Silent Ridge enters tapped.
{T}: Add {B}.
Desertcycling {1}{B} ({1}{B}, Discard this card: Search your library for a Desert card, reveal it, and put it into your hand, then shuffle.)

When Silverhorn Battlemaster enters, put a +1/+1 counter on up to two target Warriors you control.
Whenever Silverhorn Battlemaster deals combat damage to a player, permutate. (You may remove a counter from a creature you control. If you do, put two +1/+1 counters on a different creature you control.)

Double strike
Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
Whenever Sisters Suzakazi attacks, if you control another creature named Sisters Suzakazi, it deals 3 damage to any target.

Flying
When Sky-Torrent Navigator enters, forebode. If you control two or more Pirates, forebode again. (To forebode, create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.”)

Lifelink
When Slaffield Work-Hauler enters, create a 0/2 white Ox creature token for each enchantment you control.
Whenever an enchantment you control enters, Oxen you control get +1/+1 until end of turn.

Identity — As long as you control at least two other creatures that share a creature type with Slicing Steer, Slicing Steer and creatures you control that share a creature type with it get +1/+0 and have menace.

When Smirk enters, add the top two cards of your library to your evil plan. (Look at them, then exile them face-down. You may pay {7} once a turn as a sorcery to cast any number of cards in your evil plan without paying their mana costs.)
Whenever you cast your second spell each turn, you draw a card and you lose 2 life.

Mimic—Discard a card (Discard a card as a sorcery: This takes the shape of your choice.) [1/1]
[Shape 1] Menace
Soulshifter gets +1/+1 for each creature card in your graveyard. [1/1]
[Shape 2] Deathtouch
Whenever Soulshifter deals combat damage to a player, you may return target creature card from your graveyard to your hand. [2/2]

Whenever Sower of Sabne's Harvest enters or attacks, align X, where X is your fealty to Forests. (Choose modes with total ★ less than or equal to the number of Forests you control. You may choose modes multiple times.)
• ★★ — Put a +1/+1 counter on target creature.
• ★★★ — Exile target artifact or enchantment.
• ★★★★★ — You gain 5 life.

Menace
Whenever you cast a cryptic spell, you may return target creature card from your graveyard to your hand. (Artifacts, enchantments and modal spells are cryptic.)

Equipped creature gets +3/+3.
Whenever equipped creature attacks, draw a card.
Equip {5}
Equip creature you don't own {0}

Flying
{2}, Exile an instant or sorcery card from your graveyard: Spellbone Screecher deals 1 damage to any target.