msem-instigator

Exile target attacking or blocking creature with power 4 or less.

Flying (This creature can't be blocked except by creatures with flying or reach.)

Sunwing has flying as long as it's your turn.

Enchant creature
Enchanted creature gets +3/+3, has trample, and can only attack alone.

Whenever you cast a spell, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Target permanent you control becomes a 2/2 creature with flying in addition to its other types until end of turn.

Target creature gets +2/+0 until end of turn and gains “When this creature dies, return it to the battlefield tapped under its owner's control.”

Menagerie — When Supply Hauler enters, if there are five or more creature types among creatures you control, you may search your library for an artifact card, reveal it, put it into your hand, then shuffle.

Supply Run costs {2} less to cast if a creature you controlled attacked this turn and wasn't blocked.
Draw two cards.

Equipped creature has vigilance and “{T}: Add one mana of any color.”
Equip {1}

{2/R}: Suraj Outrider gets +1/+0 until end of turn.

Target creature gets +3/+0 and gains first strike until end of turn.

Identity — Sureshot Recruit has reach as long as you control at least two other creatures that share a creature type with it.

Prowess
Whenever you cast a noncreature spell, Surestrike Elite gains first strike until end of turn.

Target creature gets +2/+2 and gains trample until end of turn.
Reprise {2}{R} (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.)

Enchant creature
Enchanted creature has haste and first strike.

Until end of turn, target creature gets +1/+1 and gains lifelink.

When Surveyor's Rifle enters, rediscover a land card. (Look at the top card of your library. You may reveal it and put it into your hand if it's a land card. Otherwise, put it back or into your graveyard.)
Equipped creature gets +2/+1.
Equip {3}

Regenerate target creature. (The next time that permanent would be destroyed this turn, it isn't. Instead tap it.)

Return up to one target creature card and up to one target land card from your graveyard to your hand.

Prowess
When Surviving Scavengers enters, you may draw a card, then discard a card.

When Suspect Concoctions enters, put a +1/+1 counter on target creature.
{4}, Sacrifice Suspect Concoctions: Put two +1/+1 counters on target creature. (A suspected creature has menace and can't block.)

Enchant land
Enchanted land has “{W}, {T}: You gain 2 life.”

Swallowed by the Earth deals 4 damage to target creature. Destroy all Equipment attached to that creature.

Flying
When Sweeper Drone enters, create a Function token with “Put a +1/+1 counter on each creature named Sweeper Drone you control.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

You may tap two untapped red creatures and/or planeswalkers you control with different names rather than pay this spell's mana cost.
Exile the top two cards of your library. Until the end of your next turn, you may play those cards.