msem-instigator

Enchant creature
Enchanted creature gets +3/+0 and has first strike.

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

Equipped creature gets +1/+1 and has haste.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Choose one —
• Destroy target creature with flying.
• Destroy target artifact.

Exile up to one target artifact or enchantment.
Coalesce {5}{G} (You may cast this from your graveyard for {5}{G}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Enchant creature
When Strike Fear enters, draw a card.
When enchanted creature attacks, target creature can't block this turn.

Striptide deals 1 damage to target creature. Unattach all artifacts from it. It becomes red until end of turn.
Draw a card.

Create a Treasure token.
Showcase {2}{R} (Then if you cast this for its showcase cost, create a 1/1 red Bard creature token that can't block and exile this. Whenever it attacks, you may cast a free copy of this.)

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.

Target creature gets +2/+1 and gains trample until end of turn. Create a tapped Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Bulwark — {2}{G}: Stronghold Recruit gets +2/+2 until end of turn. Activate only once each turn and only if you control a creature with toughness 4 or greater.

Whenever another Warrior creature you control attacks, you may return Stubborn Blademate from your graveyard to the battlefield tapped and attacking. If you do, sacrifice it at end of combat.

Defender
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
{T}: Student of Lightning deals damage equal to its power to target player.

Whenever Student of the Coil attacks, target creature gains poisonous 1 until end of turn. (Whenever that creature deals combat damage to a player, that player gets a poison counter.)

Improve {G} ({G}: 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.)
Whenever an Elf you control dies, you may search your library for a land card, reveal it, put it into your hand, then shuffle.

If you've lost life this turn, you may cast this spell as though it had flash.
Return X target cards with different mana values from your graveyard to your hand. Put Studies Past on the bottom of its owner's library.

Search your library for up to two creature cards and reveal them, then shuffle. Put one on the bottom of your library and the rest on top.

Stunning Cascade enters tapped.
{T}: Add {U} or {R}.
{2}{U}{R}, {T}, Sacrifice Stunning Cascade: Draw a card.

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
Whenever a creature you control becomes renowned, you may have it fight target creature you don't control. (Each deals damage equal to its power to the other.)

At the beginning of combat on your turn, if you control six or more lands, put a +1/+1 counter on target creature you control.

As Sturdy Outpost enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {G}, {W}, or {U}.

Concord — At the beginning of combat on your turn, if there are four or more card types among permanents you control, Sturdyshell Hammerclaw gets +2/+1 and gains trample until end of turn.

({T}: Add {B}.)
As Stygian Dunes enters, you may pay 1 life. If you don't, Stygian Dunes enters tapped.

Substack Ports enters tapped.
{T}: Add {U} or {B}.
{U}{B}, {T}, Sacrifice Substack Ports: Conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)

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.)
At the beginning of your end step, Substack Sniper deals 1 damage to you and to each cursed opponent.