msem-instigator

Whenever you cast a spell with mana value greater than Script Jockey's power, put a +1/+1 counter on Script Jockey.

Haste
Frenzy 2 (Whenever this creature attacks and isn't blocked, it gets +2/+0 until end of turn.)

At the beginning of combat on your turn, if you cast both a creature spell and a noncreature spell this turn, untap up to one target land you control. It becomes a 3/1 red Sand creature with haste in addition to its other types until end of turn.

{2}{R}: Target creature can't block this turn.

When Seafloor Cache enters and when you sacrifice it, create a Treasure token.
{1}{R}, Sacrifice Seafloor Cache: Draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)

Sear Flesh deals 3 damage to target creature or planeswalker. If you've cast another spell this turn, it deals 5 damage instead.

When Sear, Forged of Lava enters, create a 3/3 red Panda creature token, then attach it to that token.
Equipped creature gets +3/+3, has flying, haste, and “Whenever this creature dies, it deals 3 damage to target opponent or planeswalker.”
Equip {2}{R}{R}

Searing Blasphemy deals 2 damage to target creature. If that creature is an Angel, Searing Blasphemy deals 5 damage instead.

This spell costs {2} less to cast if you activated an ability that's not a mana ability this turn.
Searing Grace deals 3 damage to any target.

Target creature gains winnow until end of turn if you attacked this turn. Searing Insult deals 2 damage to that creature. (Damage dealt to it also causes its controller to lose that much life.)

Reverberate {3}{R} (When you cast this spell, copy it if you paid its reverberate cost. You may choose new targets for the copy.)
Searing Pulse deals 2 damage to any target.

Haste
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.)

Menace
Whenever Searing Sandwurm is dealt damage, it deals that much damage to target player or planeswalker.

Target permanent you control deals 2 damage to any target.
Inscribe {2}{R}{R} ({2}{R}{R}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Flying
Whenever Searshot Dragon deals combat damage to a player, it deals that much damage to target creature that player controls.
{1}{R}: Searshot Dragon gets +1/+0 until end of turn.

Whenever a permanent you control leaves the battlefield, Second-Day Slayings deals 1 damage to each opponent.

Breach (Whenever this deals combat damage to a player, you may have it become an Aura Curse until your next turn. Attach it to that player.)
Each cursed opponent must attack with at least one creature each combat if able.

When Seishin Rageshaper enters, create a 2/2 colorless Spirit creature token.
Colorless creatures you control have haste.

When Seishin Smokeshaper enters, create a 2/2 colorless Spirit creature token.
Whenever you cast a noncreature spell, colorless creatures you control get +1/+1 until end of turn.

Destroy target land. Add {R}{R}.

Seismic Strike deals damage to target creature equal to the number of Mountains you control.

Instant and sorcery spells you cast cost {1} less to cast.
Rapport — Whenever Selma Lappowen and at least one other creature you control become tapped, exile the top card of your library. Until end of turn, you may play that card.

Until end of turn, target creature you control gains double strike and trample. Sacrifice it at the beginning of the next end step.
Draw a card.

Settlement Scout can't be blocked if you control an attacking creature with greater power than it.
Revive {3}{R} ({3}{R}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost. Activate this ability only any time you could cast a sorcery.)

When Sha'Iv's Scout enters, adjudicate. (Create a white Aura enchantment token with enchant creature and “Sacrifice this token: Untap enchanted creature” attached to target creature.)
Whenever an Aura you control enters, target creature can't block this turn.