msem-instigator

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a creature card that shares a creature type with the sacrificed creature with mana value less than or equal to X plus the sacrificed creature's mana value, put it onto the battlefield, then shuffle.

Reveal the top five cards of your library. Put one of those cards into your hand. Target opponent chooses two of those cards. Exile the chosen cards, then put the rest into your hand.

Whenever you cast a spell, sacrifice a permanent and draw a card.
Exile three cards from your graveyard: Counter target noncreature spell unless its controller pays {1}.

At the beginning of your end step, for each opponent, destroy up to one target creature that player controls with power less than or equal to the amount of life that player lost this turn.
{3}{R}: Selezzar, Tyrant of Endak deals 2 damage to each opponent.

Create a 1/1 colorless Construct artifact creature token. If you control an artifact, create two of those tokens instead.

Enchant creature
Enchanted creature gets +1/+1 and has lifelink.

Enchant creature
When Selfish Epiphany enters, search your library for a card and put that card into your hand. Then shuffle.
Enchanted creature has indestructible and can't be sacrificed.

Whenever a Survivor you control dies, you draw a card and you lose 1 life.

{3}: Sellsword Contraption becomes the creature type of your choice until end of turn.

Instant and sorcery spells you cast cost {1} less to cast.
Rapport — Whenever Selma Lappowen and at least one other creature you control become tapped, exile the top card of your library. Until end of turn, you may play that card.

When Seluriel's Blessing enters, put a +1/+1 counter on each creature you control.
Creatures you control enter with an additional +1/+1 counter on them.
Creatures you control with counters on them have vigilance and indestructible.

[+1]: You gain 1 life. Put a +1/+1 counter on up to one target creature.
[–3]: Exile target creature. Its controller gains life equal to its power.
[–8]: You get an emblem with “Creatures you control get +1/+1 and have double strike and lifelink.”

Until end of turn, target creature you control gains double strike and trample. Sacrifice it at the beginning of the next end step.
Draw a card.

Whenever a quest counter is put on a permanent you control, upgrade Selvar, the Seeker. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• First strike
• Vigilance
• Reach
• Trample
• Lifelink

Deathtouch
Whenever another creature you control dies, each opponent loses 1 life.
{2}{W}: Create a 1/1 colorless Servo artifact creature token.

When you cast Senaturian Centurion, reveal cards from the top of your library until you reveal a creature card with mana value 2 or less. Copy that card, then put the revealed card into your hand. You may cast the copy without paying its mana cost. Put the revealed cards on the bottom of your library in a random order.

Senaturian Legion gets +1/+1 for each other creature on the battlefield named Senaturian Legion.
A deck can have any number of cards named Senaturian Legion.

Return target non-Horror creature to its owner's hand. Scry 1.

Return up to one target creature you control and up to one target creature you don't control to their owners' hands.

When Sending Stones enters, harmonize twice. (To harmonize, trigger up to one harmony of a permanent you control.)
If you would harmonize, you may trigger a harmony of a permanent card in your graveyard instead.

At the beginning of your draw step, draw an additional card and you lose 1 life. Then if you have six or fewer cards in hand, sacrifice a creature.

Choose one —
• Target permanent gains protection from instants and sorceries until end of turn.
• You gain 3 life.
• Draw a card.

Destroy target creature. Trigger a death knell of a permanent you control.

Death knell — Put a +1/+1, flying, lifelink, or menace counter on Senn, the Haunting Gaze, then trigger a death knell of another permanent you control. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)

When Sensational Festivities enters or at the beginning of your upkeep, you may draw a card. If you do, each opponent may draw a card, then discard a card.