msem-instigator

Whenever Sunken One attacks, target creature defending player controls gets -13/-0 until end of turn.
Islandcycling {2} ({2}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

Sunlit Ruins enters tapped unless you control a Swamp.
{T}: Add {G} or {W}.

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

Sunswept Grange enters tapped. When it enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Add {R} or {W}.

Whenever Supreme Mechanothurge or another artifact you control enters, up to one target artifact you control becomes a copy of another target artifact or creature you control, except it's an artifact in addition to its other types.

Menace, reach
When Surfacing Horripede enters, surveil 2.

Whenever equipped creature attacks, choose one —
• Tap target creature.
• Draw a card, then discard a card.
• Exile target card from a graveyard.
Equip {3}

Choose up to one nonland permanent. Return the rest to their owners' hands.

Destroy target tapped creature.

When Sword of the Heavens enters, attach it to target creature you control.
Equipped creature gets +2/+2 and has flying, vigilance, and “Whenever this creature attacks, you may search your library and/or graveyard for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.”
Equip {3}

Target creature gets +2/+2 until end of turn. Draw a card if that creature has a counter on it.

Reach, trample
Tallowkeep enters with two wax counters on it.
Whenever Tallowkeep attacks, remove a wax counter from it. Then if Tallowkeep has no wax counters on it, sacrifice it.
Whenever another artifact you control enters, put a wax counter on Tallowkeep.

Colossal 3—{7}{R}{R} (You may cast this for its colossal cost to have it enter with three +1/+1 counters; or pay {7}{R}{R} as a sorcery: Put three +1/+1 counters on it if it has none.)
Flying
Each creature you control with a counter on it has double strike.

This spell costs {2} more to cast for each target beyond the first.
Choose one or more —
• Exile target enchantment.
• Target player creates two tapped 1/1 white Soldier creature tokens.
• Taranika's Endeavor deals damage equal to the number of creatures you control to target creature or planeswalker.

Flying
Whenever another Spirit or another creature with flying you control enters, put a +1/+1 counter on Tattergeist.

{T}: Tap target creature.
{T}: Draw a card, then discard a card.
Whenever another artifact you control enters, untap Telemin Architect.

Exile target creature an opponent controls. Each player may search their library for a basic land card and put that card onto the battlefield tapped. Then each player who searched their library this way shuffles.

When Terraformer's Globe enters, draw a card.
{T}: Target land you control becomes the basic land type of your choice until end of turn.

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Vigilance
When Terror of the Ulvenwald enters, target creature gets +3/+3 until end of turn.
Forestcycling {2} ({2}, Discard this card: Search your library for a Forest card, reveal it, put it into your hand, then shuffle.)

When Thallid Cultivator dies, mill four cards. Return a creature card milled this way to your hand.

Flying
At the beginning of combat on your turn, gain control of up to one target creature an opponent controls. If you do, untap it, and it gets +4/+4 and gains flying and haste until end of turn. Sacrifice it at the beginning of the next end step.

Enchant creature you control
When Thassa's Benefaction enters, scry 2.
Enchanted creature gets +1/+0 and has flying.

Heroic — Whenever you cast a spell that targets Thassa's Shoreguards, tap target creature an opponent controls. It doesn't untap during its controller's next untap step.
Whenever Thassa's Shoreguards deals combat damage to a player, draw a card.