msem-instigator

Whenever you cast a spell that doesn't share a color with Stinging Hunter, each opponent loses 1 life.

Reach
Stonebark Incinerator gets +2/+0 and has trample as long as you control a Dwarf.
Stonebark Incinerator gets +0/+2 and has vigilance as long as you control a Elf.

When Stonefall Golem leaves the battlefield, destroy target permanent.

Whenever Stonehoof Familiar is dealt damage, put a +1/+1 counter on it. (It must survive the damage to get the counter.)
Menagerie — As long as there are five or more creature types among creatures you control, all damage that would be dealt to you or other permanents you control is dealt to Stonehoof Familiar instead.

Improve {1} ({1}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
{3}{W}: Return target nonland permanent card with mana value 1 or less from your graveyard to your hand. This ability cost {1} less to activate for each counter on Stoneport Provisioner.

At the beginning of your upkeep, if Stonework Infantry is on the battlefield, each player returns all cards named Stonework Infantry from their graveyard to the battlefield.

Flying
Stormcloud Drake gets +1/+0 for each instant and sorcery card in your graveyard.
Whenever Stormcloud Drake attacks, tap target creature defending player controls.

Other artifacts you control have ward {1}.
Overcast — Whenever you cast an artifact creature spell, if {C} was spent to cast it, it enters with an additional +1/+1 counter on it.

Vigilance
{4}{U}: Draw a card.

Prowess, haste

Whenever one or more creatures you control deal combat damage to a player, exile a nonland card from that player's graveyard. Copy it. You may cast the copy. (You still pay its costs, including color. Copies of permanents enter as tokens.)

At the beginning of your upkeep, you may pay 2 life. If you do, exile the top card of target opponent's library. If a nonland card is exiled this way, copy it. You may cast the copy. (You still pay its costs, including color. Copies of permanents enter as tokens.)

{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.

Flying
Prophecy {0} (Once each turn, you may exile a card with prophecy as you reveal it. When you do, you may cast it for its prophecy cost as long as it's exiled.)

Flash
Flying
When Strange Sights dies, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Whenever another creature you control enters, put your choice of a +1/+1 counter, a trample counter, or a haste counter on it.

Wither (This deals damage to creatures in the form of -1/-1 counters.)

When Street Performer enters, create a 2/1 blue Illusion creature token with “When this creature becomes the target of a spell or ability, sacrifice it.”

Menace
Deploy 4 (As this enters, you may tap any number of other creatures you control with total power 4 or more.)
When Street Raider enters deployed, discard your hand, then draw three cards.

When Street Stalker enters, target opponent loses 1 life for each creature you control named Street Stalker.

Whenever you make first contact, target creature you control can't be blocked by Humans this turn. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)

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

Whenever Strict Instructor attacks, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Tap or untap another target permanent.

Whenever you cast a spell, if it isn't your main phase, scry 1.

Strider Engine enters tapped and with a -1/-1 counter on it unless you spent at least three colors of mana to cast it.