msem-instigator

Defender
{T}: Scale-Crown Archer deals 1 damage to each opponent.
Prismatic — Whenever you cast a multicolored spell, untap Scale-Crown Archer.

Enchant creature
Enchanted creature gets +4/+4 and has trample.
When enchanted creature dies, create a 4/4 green Beast creature token with trample.

Enchant player
When Scaleblight's Quarry enters, you may have target creature you control deal damage equal to its power to target creature enchanted player controls.
Whenever enchanted player becomes the target of a spell you control, you gain 1 life.

Whenever another creature you control enters, if its power is greater than Scalebruiser's power, put a +1/+1 counter on Scalebruiser.
As long as Scalebruiser's power is 4 or greater, each other creature you control enters with an additional +1/+1 counter on it.

{3}{G}: Scaled Devestator gets +1/+1 and gains trample until end of turn.

{R}, Discard a card: Target creature blocking Scaled Mindreaver gains winnow until end of turn. (Damage dealt to it also causes its controller to lose that much life.)

Put a +1/+1 counter on target creature. That creature gains first strike until end of turn.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

Haste
When Scaled Thundercaller enters, target creature gains winnow until end of turn. (Damage dealt to it also causes its controller to lose that much life.)

Poisonous 4 (Whenever this creature deals combat damage to a player, that player gets four poison counters.)
At the beginning of combat on each of your turns, if an opponent is poisoned, creatures you control gain trample until end of turn.

Equipped creature gets +1/+1.
Equipped creature has “When this creature dies, if it's not a token, create a token that's a copy of it except it's a colorless Spirit Dragon with flying in addition to its other abilities.”
Equip {2}

When Scaleshredder enters, you may have it consume. If you do, reveal cards from the top of your library until you reveal a creature card. Put that card onto the battlefield and the rest on the bottom of your library in a random order. (To consume, sacrifice another creature or exile a creature card from your graveyard.)

Prowess
Whenever you cast a noncreature spell, create a 3/3 red Dragon creature token with flying.

When Scanning Module enters, crystallize. (Put a +1/+1 counter on a creature you control or create a Treasure.)
Equipped creature gets +1/+1.
Equip {1}

Remove a -1/-1 counter from target creature. That creature gets +2/+2 until end of turn.

Enchant player
Whenever enchanted player taps a nonbasic land they control, that land doesn't untap during its controller's next untap step.

Target creature you control gains haste until end of turn. Create a token that's a copy of that creature, then exile that token.

Haste
Motley — At the beginning of your upkeep, if there are five or more names among nonland permanents you control, Scarletblood Hound deals 3 damage to each opponent.

{2}{G}: Scarred Brawler gets +2/+2 until end of turn.

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

Scathing Review deals 2 damage to target creature. If you control an artifact, Scathing Review deals 2 damage to that creature's controller.

Target permanent you control gains hexproof and indestructible until end of turn. You gain 2 life.

Scavenger Holdout enters tapped.
When Scavenger Holdout enters, you may pay {3}. If you do, create two 1/1 green Scout creature tokens.
{T}: Add {C}.

As an additional cost to cast Scavenger's Skill, you may reappropriate. (To reappropriate, exile exactly two cards from your hand and/or graveyard.)
Scavenger's Skill deals 3 damage to target creature or planeswalker. When that permanent dies this turn, if Scavenger's Skill's additional cost was paid, draw a card.

{3}, {T}: Draw a card.
Crew 3 (Tap any number of creatures you control with total power 3 or greater: This Vehicle becomes an artifact creature until end of turn.)