msem-instigator

Whenever Savvy Saboteur attacks, target creature defending player controls can't block target creature you control this turn.

Whenever you cast a spell, Scorned Figurant gets +1/+1 until end of turn.

Scoundreleo enters with a +1/+1 counter on it if a creature you controlled dealt combat damage to a player this turn.

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

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

As long as it's your turn, Shell Merc has first strike and prowess.

Whenever you sacrifice a permanent, put a +1/+1 counter on Shipment Overseer.
Surpass {5}{R} ({5}{R}: Transform this creature. This costs {1} less to activate for each counter on it. Activate only as a sorcery.)

Haste
Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Legendary creatures you control have haste.

When Slaug's Warhowler enters, create a 1/1 red Goblin creature token with haste.
When Slaug's Warhowler dies, you may discard a card. If you do, draw a card.

Slinking Raider can't be blocked by creatures with greater power.
Whenever Slinking Raider deals damage to a player or noncreature permanent, put a +1/+1 counter on it.
Surpass {5}{R} ({5}{R}: Transform this creature.
This costs {1} less to activate for each counter on it. Activate only as a sorcery.)

First strike
{2}{R}: Monstrosity 2. (If this creature isn't monstrous, put two +1/+1 counters on it and it becomes monstrous.)

When Smoldering Husk dies, it deals 2 damage to any target.
{2}{R}: Smoldering Husk gets +2/+0 until end of turn.

Advance {2}{R} (Cast this for {2}{R} to advance it as it enters. {2}{R}: Advance this as a sorcery.)
Haste
Whenever Soulblade Warrior advances, it gets +2/+0 until end of turn.

Haste
Storm Entity enters with a +1/+1 counter on it for each other spell cast this turn.

Whenever a permanent you control becomes tapped, Storm Servant gets +1/+1 until end of turn.

Prowess, haste

{1}, {T}: Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
{2}, {T}, Exile an instant or sorcery card from your graveyard: Stormvolt Apprentice deals 1 damage to each opponent.

Harmony — Target creature gains haste until end of turn.
When Streetside Entertainer enters, harmonize. (Trigger up to one harmony of one permanent you control.)

Sunset Cliffs Hunter gets +1/+0 and has first strike as long as a player controls a permanent with a bounty counter on it.

Sycophantic Aristocrat gets +2/+1 as long as you control another Noble.

Haste
Art of war — At the beginning of your end step, if Teikoku Skirmisher dealt damage to an opponent this turn, put a +1/+1 counter on it.

Prowess
Whenever you cast an instant or sorcery spell, Tirenan Pyromancer deals 1 damage to each opponent.

{2}{B}: Return Torchlight Tormentor from your graveyard to your hand. If you do, each opponent loses 1 life.

Haste
Sacrifice a land: Trail Blazer explores. You may put a basic land card from your hand onto the battlefield tapped. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then you may put that card in your graveyard.)

Rhapsody {4}{R}{R} (Pay {4}{R}{R} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
Double strike