msem-instigator

Whenever Ravaging Tyrant enters or attacks, each opponent loses 3 life, discards a card, and sacrifices a creature or planeswalker.

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.

Once each turn, when Rova, the Fleshweaver enters or you attack with one or more Horrors, you may put a +1/+1 counter on each creature you control. Then if Rova isn't a token, untap each land you control. Until your next turn, you may cast permanent spells as though they had flash.
{2}{G}{G}, Discard Rova: Create a token that's a copy of Rova, the Fleshweaver, except it's 4/4 and isn't legendary. Activate only as a sorcery.

Trample
Whenever Ruinous Glutton deals combat damage to a player, destroy target artifact or enchantment that player controls.

Ruins Monitor can't be blocked by more than one creature.

Trample
Players can't activate abilities of nonbasic, noncreature permanents.

Transcend (Activate as a sorcery to gain the next type and a +1/+1 counter.)
Haste
At the beginning of combat on your turn, sacrifice Sahra unless he entered the battlefield or transcended this turn.
{R}{G}: Demon — Discard up to two cards. Draw that many cards plus one.
{2}{R}{G}: Elder — Destroy each artifact and enchantment you don't control.

As an additional cost to cast this spell, pay 3 life and sacrifice a creature.

When Screams from the Deep enters, exile up to one target monocolored permanent.
As long as an opponent owns three or more cards in exile, you may have Screams from the Deep assign its combat damage as though it weren't blocked.
Evoke {5} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Return each nonland permanent you don't control to its owner's hand.
Coalesce {6}{U}{U}{U} (You may cast this from your graveyard for {6}{U}{U}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Flash
This spell can't be countered.
Whenever Shigurei attacks, you may activate an ability of a creature you control without paying its cost.
{1}{G}{U}: Target permanent becomes a colorless Island land until end of turn.

Create a 1/1 black Spirit creature token with flying for each creature card and Revelation card in your graveyard.
Coalesce {6}{G}{W}{U} (You may cast this from your graveyard for {6}{G}{W}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Siege Ent can't be blocked by creatures with power 2 or less as long as it's embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

When Sihari's Groundblazer enters, create a red Aura enchantment token named Searing Crags attached to target land. The token has enchant land, “Enchanted land's name is Charred Causeway” and “Enchanted land has {T}: This land deals 1 damage to each opponent.”

Flying, vigilance
When Silksoul Celestial enters, search your library for an enchantment or Aurashaper card, reveal it, put it into your hand, then shuffle.
When Silksoul Celestial dies, you may put an enchantment or Aurashaper card from your hand or graveyard onto the battlefield.

Skavi Behemoth can't be the target of nongreen spells or abilities from nongreen sources.

Menace
Whenever an opponent casts a spell, Skhorvall Behemoth gets -2/-2 until end of turn.

If you control seven or more creatures, you may cast Sociable Giant without paying its mana cost.
Trample

Solar Hatching deals 4 damage to each creature.
Coalesce {6}{R}{R} (You may cast this from your graveyard for {6}{R}{R}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
When Solar Hatching enters, each player chooses up to two lands they control and sacrifices the rest.

Reach
{3}, Exile Sorrowful Seeker from your hand: Draw a card. You may cast this card for as long as it remains exiled.

Spellwoven Monster can't be the target of spells or abilities in any zone.
As you cast an instant or sorcery spell, reveal cards from the bottom of your library until you reveal an instant or sorcery card. You may add that card's effects to that spell. Then shuffle.

When Spirit of the Falls enters, choose a permanent type. Return all other permanents of the chosen type to their owner's hands.
Discard two land cards: Spirit of the Falls gains hexproof until end of turn.

Steel Hunter can't attack unless you control three or more other artifacts.

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