msem-instigator

Put target artifact or enchantment with mana value less than or equal to the number of basic lands you control on the bottom of its owner's library.

[+1]: Up to one other target permanent gains hexproof and indestructible until your next turn.
[–3]: Destroy target tapped permanent.
[–7]: You get an emblem with “If you would lose the game, instead exile this emblem, shuffle all cards you own that aren't on the battlefield into your library, then draw seven cards. Your life total becomes 40.”

({T}: Add {G}, {U}, or {R}.)
Pristine Dominion enters tapped.

Whenever Toxic Lurker attacks, you may have target creature defending player controls get -2/-1 until end of turn.

Hexproof, indestructible
You don't lose the game for having 0 or less life.
For each 1 life you would lose while you have 0 or less life, instead put a -1/-1 counter on a creature you control with toughness 1 or greater.

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

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Remove a +1/+1 counter from Kor Skyknight: It gains flying until end of turn.

Whenever another creature you control enters, put a +1/+1 counter on each creature you control with lesser power or lesser toughness than that creature.

Whenever Qalami Barbarian attacks, you may discard a card. If you do, it gets +1/+2 and gains menace until end of turn.

Once each turn, when a creature card is put into your graveyard from anywhere, create a 1/1 blue and black Bird creature token with flying and “When this creature deals combat damage to a player, sacrifice it. If you do, draw a card.”
Whenever three or more creatures you control deal combat damage to a player, that player loses 1 life for each card in your hand.

{T}: Create a Treasure token.
{W}{U}{B}{R}{G}: Until end of turn, Guardians of Kallian's Tomb becomes a 5/5 Ox artifact creature and gains trample and “Whenever this creature attacks, defending player sacrifices a permanent unless they have you draw two cards.”

Whenever Maritime Thug becomes tapped, it deals 1 damage to each opponent.

Trample
{1}{G}{W}, Discard Enduring Force: Search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.
{G}{W}: Return Enduring Force from your graveyard to your hand. Activate only as a sorcery.

When Wild Hermit dies, create a 2/2 white Cat creature token.
Revive—{3}{G}{G}, Sacrifice a creature. ({3}{G}{G}, Sacrifice a creature, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Flying
{R}: Slyten Ignitor gets +1/+0 until end of turn.

Target creature gets +1/+1 until end of turn. Untap that creature.
Fabled {2}{W} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that creature.)

First strike, hexproof

When Yron Bay Sentinel enters, draw a card.

Lantern-Bearer Belle gets +2/+0 and has flying as long as you've sacrificed a permanent this turn.

Altar of Creation enters tapped.
{T}: Add {U}.
{T}: Add {B} or {G}. Altar of Creation doesn't untap during your next untap step unless you control an Angel creature.

First strike
Creatures with power greater than Gao'Wu, Master Soothsayer's power can't attack.

Put a +1/+1 counter on each creature you control. (Then exile this card. You may cast the creature later from exile.)

Chosen one ({W}{U}{B}{R}{G}: Transform this permanent.)
When Sower of Wishes enters, reveal the top three cards of your library. Put all land cards revealed this way into your hand and the rest back on top in any order.

Exile target creature or planeswalker. You gain 4 life.

{T}: Add {C}.
{T}, Sacrifice Shiftscape Crag: Choose a basic land type other than Mountain. Create a colorless land token that's a Mountain and the chosen basic land type. Activate only during your upkeep.