msem-instigator

{R}, {T}: Sandbluff Slinger deals 1 damage to any target.
Quickdraw {1}{R} (When a creature you control blocks or becomes blocked, you may cast this spell for {1}{R}.)

Creatures you control get +1/+1 until end of turn. Soldiers you control also gain first strike until end of turn.

Flying
Whenever Sandslinger attacks, you may tap target creature if you've gained life this turn.

Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)
When Sandstrider enters, put a +1/+1 counter on target creature.

Whenever you gain life, target opponent loses that much life.

{B}, Pay 1 life: Target creature's controller sacrifices it unless that player pays 1 life.
{B}, Sacrifice a creature: You gain life equal to the sacrificed creature's power.

At the beginning of your upkeep, you gain 1 life for each color among permanents you control.
{W}{U}{B}{R}{G}, Sacrifice Sartha's Studies: Double your life total.

Flying, vigilance, lifelink
During each of your turns, you may cast a multicolored spell from your graveyard.

Target creature you control fights target creature you don't control. (Then exile this card. You may cast the creature later from exile.)

Other creatures you control that entered this turn have haste and lifelink.
{T}: You may put a creature card from your hand onto the battlefield.

{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.)

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.)

Advance {1}{B} (Cast this for {1}{B} to advance it as it enters. {1}{B}: Advance this as a sorcery.)
Whenever Scarcrawler advances, you lose life equal to its power, then put a +1/+1 counter on it.

At the beginning of your end step, each opponent loses 1 life for each permanent they own that you control.

Harness (You may tap a creature you control as you cast this spell. If you do, reduce this spell's mana cost by that creature's power.)
Target creature gets -X/-X until end of turn.

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

Exile target creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.

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

Target creature gets +1/+0 for each land you control and gains trample until end of turn.
Orchestrate {1}{G} (You may exile this card from your hand anytime you could cast a sorcery for its orchestrate cost. When you next resolve a spell, you may cast this from exile without paying its mana cost.)

Enchant creature or land
Whenever enchanted permanent becomes tapped for the first time each turn, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then put the card back or put it into your graveyard.)

Up to three target creatures each get +1/+1 until end of turn.

Whenever one or more nontoken Merfolk you control attack, create a 2/1 red Merfolk creature token.

Indestructible
Whenever a creature an opponent controls dies, put five +1/+1 counters on Scion of Death.

This spell costs {2} less to cast if its target has the same name as a card in a graveyard.
Scoff deals 3 damage to any target.