msem-instigator

Barren Vista enters tapped.
{T}: Add {U} or {B}.
{1}, {T}: Add one mana of any color.

Strange Harbor enters tapped unless you have 15 or less life.
{T}: Add {U} or {R}.

({T}: Add {U} or {R}.)
Torrid Geysers enters tapped unless you control two or more basic lands.

When Ethersketch Blueprints enters, create a 1/1 blue Thopter artifact creature token with flying.
{2}, Sacrifice Ethersketch Blueprints: Draw a card.
Monument {5}{B}{B} (You may cast this transformed from your graveyard for its monument cost. Exile it if it would leave the battlefield or not resolve.)
Ascend {4}{W} ({4}{W}: Exile this permanent, then return it to the battlefield transformed. Ascend only as a sorcery.)

Whenever Babbling Experiment or another creature you control enters, target player mills two cards.

When this creature enters or leaves the battlefield, create a tapped 2/2 black Zombie creature token.

Tranquil Shrine enters tapped.
When Tranquil Shrine enters, if you don't control a legendary creature, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

You gain 3 life.
Amass Soldiers 1. (Put a +1/+1 counter on an Army you control. It's also a Soldier. If you don't control one, create an 0/0 black Soldier Army creature token first.)

{T}, Sacrifice Worldshaper Adept: Choose two basic land types. Create a tapped colorless land token of the chosen types.

Create X 1/1 green Saproling creature tokens, then populate. (Create a token that's a copy of a creature token you control.)

For each pair of basic land types, create a tapped colorless land token of those types. (The basic land types are Plains, Island, Swamp, Mountain, and Forest.)

Counter target spell that targets you or a permanent you control.
Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Whenever Sandbluff Inciter attacks, it deals damage to defending player equal to the number of tapped creatures you control.

Submerge all creature cards in graveyards. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

When Ralezza's Disciple enters, if you control an enchantment, you gain 3 life.

Whenever a creature you control enters for the second time each turn, it gains haste until end of turn. You may have it get +1/+1 until end of turn.

Tendrils of Corruption deals X damage to target creature and you gain X life, where X is the number of Swamps you control.

Flash
Enchant creature you control
Enchanted creature gets +3/+3 and has lifelink and indestructible.

Take an extra turn after this one. During that extra turn, you may cast spells you own not named See the World from outside the game by tapping an untapped Scout you control in addition to paying their mana costs.
Exile See the World.

Target opponent reveals their hand. You may choose a noncreature, nonland card from it. If you do, that player discards that card. Otherwise, they lose 3 life.

Whenever Whisperer of Fortunes attacks, the next card you foretell this turn costs {0} to foretell.
Whenever you cast a foretold spell, put a +1/+1 counter on Whisperer of Fortunes. It gains flying until end of turn.

Target player discards two cards.
Coalesce {8}{B} (You may cast this from your graveyard for {8}{B}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

{X}{G}: Put X +1/+1 counters on target noncreature, nonplaneswalker permanent you control. It becomes an Elemental creature with base power and toughness 0/0 in addition to its other types. (This effect lasts indefinitely.)

Parasitic Bloodsucker gets +1/+1 as long as you control a Swamp.
{2}{B}: Parasitic Bloodsucker gains lifelink until end of turn