msem-instigator

Target creature gets +1/+0 for each land you control and gains trample until end of turn.
Orchestrate {1}{G} (You may exile this card from your hand anytime you could cast a sorcery for its orchestrate cost. When you next resolve a spell, you may cast this from exile without paying its mana cost.)

Enchant creature or land
Whenever enchanted permanent becomes tapped for the first time each turn, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then put the card back or put it into your graveyard.)

Flash
When Scholar of Necromancy enters, if a creature died this turn, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Flash
When Scholar of Reflections enters, you may switch target creature's power and toughness until end of turn.

Scholar of the Staff can't block.
Inspired — Whenever Scholar of the Staff becomes untapped, up to one target creature can't block this turn.

Flying
{1}{U}, Sacrifice Scholar's Assistant: Draw a card.

Attacking creatures get -3/-0 until end of turn.

Up to three target creatures each get +1/+1 until end of turn.

Schoolmaster gets +1/+1 for each other Merfolk you control.
When Schoolmaster enters, create a 1/1 white Merfolk creature token.

Whenever one or more nontoken Merfolk you control attack, create a 2/1 red Merfolk creature token.

When Scintillating Tome enters, choose a nonbasic card name.
{T}: Scry 1, then you may reveal the top card of your library. If a card with the chosen name is revealed this way, put it into your hand.

Scion of Belmord has lifelink 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.)

Indestructible
Whenever a creature an opponent controls dies, put five +1/+1 counters on Scion of Death.

Disgraced 1 (This enters with a -1/-1 counter. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)
Whenever you put one or more -1/-1 counters on Scion of Fiends or another creature, Scion of Fiends deals that much damage to each opponent.

Flying
Civilized — Scion of Sannuria has vigilance as long as you control an artifact, a creature, and an enchantment.

When Scion of Sarrithaz enters, create a 2/2 black Zombie creature token.
{2}{B}, Sacrifice a creature: Draw a card.

Poisonous 2 (Whenever this creature deals combat damage to a player, that player gets two poison counters.)
Snakes you control can't be blocked by creatures with power 2 or less.

First strike
Whenever Scion of the Pack enters or one or more creatures you control deal combat damage to an opponent or planeswalker, create a 2/2 green Hound creature token.

Vigilance
Other Knights and Soldiers you control get +1/+1.
{2}{B}, {T}, Sacrifice a Knight or Soldier: Destroy target creature or planeswalker. Activate only as a sorcery.

Scion of the Wild's power and toughness are each equal to the number of creatures you control.

Sacrifice Scions of Old Jidai: Target player gains life equal to the life that player has lost this turn.

This spell costs {2} less to cast if its target has the same name as a card in a graveyard.
Scoff deals 3 damage to any target.

As Scorched Copse enters, you may tap an untapped creature you control. If you don't, Scorched Copse enters tapped.
{T}: Add {R} or {G}.

As an additional cost to cast Scorched-Earth Defence, reappropriate X times. (To reappropriate, exile exactly two cards from your hand and/or graveyard.)
Scorched-Earth Defence deals X damage to each creature and each planeswalker.

Enchant creature
Enchanted creature gets +2/-2.