msem-instigator

Whenever a creature enters, destroy it unless its controller pays 3 life.

Each creature you control has base power and toughness X/Y, where X is the greatest base power among creatures you control and Y the greatest base toughness among creatures you control.

Restored Automaton enters with X +1/+1 counters on it.
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

Bloodprice—Reappropriate red. (You may cast this spell by sacrificing a creature and exiling two red cards from your hand and/or graveyard.)
Haste
Whenever Creed's Desperado attacks, if defending player has more cards in hand than you, exile the top card of that player's library. You may cast it as long as you control a Warrior, and you may spend mana as though it were mana of any color to cast it.

Harness (You may tap a creature you control as you cast this spell. If you do, reduce this spell's mana cost by that creature's power.)
Return target nonland permanent to its owner's hand. If this spell was harnessed, draw a card.

Motivate 1 (When this creature enters, you may motivate target creature with less power than this by putting a +1/+1 counter on it.)
When Goriana Tactician enters, you may tap target creature.

Tap target creature.
Fabled {3}{U} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that creature.)

Tempting Realms enters tapped unless you control two or more other lands.
{T}: Add {B}.
{T}, Pay 1 life: Add {U} or {R}.

{1}{R}: Roaring Dracowyrm gets +2/+0 until end of turn. Activate only once each turn.

Return target permanent you control to its owner's hand. (Then exile this card. You may cast the creature later from exile.)

When Growth Paradigm enters, conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)
Once each turn, when you cast a sorcery spell, you may create an X/X green Mutant creature token, where X is that spell's mana value.

Target creature gets -2/-2 until end of turn. When that creature dies this turn, its controller loses 2 life or gets a poison counter.

Tithe (When this creature enters, you may tap three other artifacts and/or creatures you control.)
When Wailing Chorus enters, each opponent discards a card. If its tithe was paid, each opponent discards two cards instead.

Whenever an embattled creature you control dies, you may return Skhorvall Eternal from your graveyard to your hand. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Lifelink
When Sacellum Visionary enters, draw a card.

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Another target creature you control gets +1/+1 until end of turn.
[Lore III] Search your library for a basic land card, put it onto the battlefield, then shuffle.

Whenever you sacrifice an enchantment, exile Kindly Pilgrim. If you do, create a 4/4 white Angel creature token with flying.

Flip a coin until you lose a flip or choose to stop flipping. Exile the top X cards of each player's library, where X is 1 plus the number of flips you won. You may play those cards until the end of your next turn, and you may spend mana as though it were mana of any color to cast those spells.

You may play lands from your graveyard.
{B}{G}, Sacrifice three lands: Return Endrison Nourisher from your graveyard to your hand.

First strike
When Enlistment Officer enters, reveal the top four cards of your library. Put all Soldier cards revealed this way into your hand and the rest on the bottom of your library in any order.

Prevent all damage that would be dealt to you and permanents you control.

Augmented — If you've spent {W}{U}{B}{R}{G} to cast spells this turn, you may play Start Over without paying its mana cost.
Put target creature or planeswalker on the bottom of its owner's library.

{T}: Add {C}.
{4}, {T}, Sacrifice Eon Campfire: Destroy target artifact or nonbasic land.

Flash
When Enlightened Lizard enters, counter target noncreature spell.