msem-instigator

Each opponent loses 1 life. Whenever you cast another spell this turn, each opponent loses 1 life.
Acquiesce (If you cast this spell from your hand, exile it as it resolves. When one or more creatures you control deal combat damage to an opponent, you may cast this card from exile without paying its mana cost.)

Vigilance, lifelink

This spell can't be countered.
Haste
Whenever a creature dealt damage by Ripper of the Fang Den this turn dies, put X +1/+1 counters on Ripper, where X is his power.

Amleth, Royal Claimant can't be blocked by creatures with power 3 or less.
At the beginning of your end step, if you control three or more tapped creatures, create a 4/4 white Angel creature token with flying and vigilance. Otherwise, create a 1/1 white Soldier creature token.

Concord — {T}, Sacrifice Disciple of Destruction: Destroy target nonland permanent. Activate only if there are four or more card types among permanents you control.

Kicker {W} (You may pay an additional {W} as you cast this spell.)
Target player sacrifices an attacking creature. If this spell was kicked, you gain life equal to the sacrificed creature's power.

Artifacts and lands enter tapped.

Inspired — Whenever Yenzu Disciple becomes untapped, each opponent loses 1 life and you gain 1 life.

When Militant's Standard enters, draw a card if you control a Merfolk.
Equipped creature gets +2/+1.
Equip {2}

Another target player reveals their hand. You may choose a nonland card from it. That player discards that card.
Fuse (You may cast one or both halves of this card from your hand.)

Whenever Ferris, the Sapphire Storm or another creature you control enters, each opponent mills X cards, where X is that creature's power.

Flying, vigilance
Whenever a land you control enters, create a 2/2 green Ox creature token.
{3}{W}, Tap three untapped Oxen you control: Put a +1/+1 counter on each creature you control.

Look at the top five cards of your library. You may reveal a land or Nomad card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
You may play an additional land this turn.

Choose target instant spell, sorcery spell, activated ability, or triggered ability. Create a Function token with its effects. Then you may pay {1}{U}. If you do, counter that spell or ability. (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell. A spell's effects includes added functions.)

({T}: Add {G} or {U}.)
Soaring Rainforest enters tapped.
{1}, {T}: Add {G}{G} or {U}{U}.

Vigilance
Avatar of Utsenchep can block any number of creatures.
All creatures able to block Avatar of Utsenchep do so.

Lifelink
Vanishing 1 (This creature enters with a time counter on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Whenever another creature you control dies, put a time counter on Dulling Necromancer.

Reach (This creature can block creatures with flying.)

{T}, Pay 1 life: Add {U} or {R}.
{2}, {T}, Sacrifice Lamplit Thoroughfare and another permanent: Draw a card. Activate only during your turn.

Menace (This creature can't be blocked except by two or more creatures.)

Whenever Dunesea Dreadstalker or another nontoken creature you control dies, 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.)

Target creature you control gets +4/+4 until end of turn.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

Put two +1/+1 counters on target creature. You gain life equal to that creature's power.

When Dunesea Merchant enters, tap up to X target creatures, where X is the number of Satrapies you control.
Satrapycycling {2} ({2}, Discard this card: Search your library for a Satrapy card, reveal it, put it into your hand, then shuffle.)

Flying
When Nest Matriarch enters, put a +1/+1 counter on another target creature you control. That creature gains lifelink until end of turn.