msem-instigator

Shu Qin enters with your choice of a flying or +1/+1 counter on him.
At the beginning of your upkeep, choose a creature in Shu Qin's pack. He gains that creature's abilities until end of turn. (Two or more creatures you control with equal power are in a pack.)

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.)

At the beginning of your upkeep, you lose life equal to the number of Armies you control, then recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)

Gain control of target nonland permanent an opponent controls. Its owner reveals cards from the top of their library until they reveal a card that shares a type with that permanent, then puts it onto the battlefield and shuffles.

Flying
Other creatures you control enter with an additional +1/+1 counter on them.
If a spell or ability an opponent controls causes you to discard Sigarda, Dawn of Mercy, put it onto the battlefield instead of putting it into your graveyard.

First strike
Whenever Sighted-Caste Knight deals combat damage to a player, draw a card.

When Sigiled Bulwark enters, search your library for a creature card and a noncreature card and reveal them. An opponent chooses one of those cards. Shuffle the chosen card into your library, then put the rest into your hand.

If a source you control would produce two or more mana, you may have it produce an additional {C}.
{4}: Exile the top card of your library. You may play it until the end of your next turn.

You may look at the top card of your library any time, and you may play Deserts from the top of your library.
[+1]: You gain 1 life. You may discard a card. If you do, draw a card.
[–2]: Sihari deals 2 damage to any target. You may play an additional land this turn.
[–4]: Create an X/X red and green Sand Elemental creature token with trample and haste, where X is the number of lands you control.

Counter target spell unless its controller pays {1} and 3 life.

Enchant creature
When Silent Call enters, draw a card.
Enchanted creature attacks each combat if able.

Flying
When Silent Griffin enters, draw three cards, then put two cards from your hand on top of your library.

As Silent Hypnotist enters, choose a noncreature card name.
Spells with the chosen name can't be cast.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.

Prevent all combat damage that would be dealt to Silent Reaver.
Prevent all combat damage Silent Reaver would deal to creatures.

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.

Whenever you discard one or more cards, create a Treasure token and draw a card. This ability triggers only once each turn.
Whenever two or more creatures you control attack, you may discard a card. If you do, target creature can't block this turn.

{2}{B/G}: Return Silthway Scuttler from your graveyard to your hand.
{2}{B/G}, Exile Silthway Scuttler from your graveyard: Put two +1/+1 counters on target creature.

When Silver Gardener enters, create a 1/1 green Saproling creature token.
Unveil {2}{G}{W} ({2}{G}{W}: Transform this. Unveil only as a sorcery.)

At the beginning of combat on your turn, target creature you control gains vigilance until end of turn. That creature can't be blocked this turn.

Trample
Whenever Simian Sentinel attacks, it gets +X/+0 until end of turn, where X is the number of lore counters on Sagas you control.

[+1]: Create a 1/1 colorless Elemental creature token. Put a loyalty counter on each planeswalker you control.
[+1]: Untap up to two target permanents.
[–7]: You get an emblem with “Whenever you create a token, draw a card.” Create three 4/4 green Chimera creature tokens.

Whenever you attack, each opponent loses 3 life unless they discard a card or sacrifice a nonland permanent. Repeat this process once.
Fleeting {B}{R} (You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)

Each creature gets -X/-X until end of turn. Destroy each artifact and enchantment with mana value X or less.

Whenever Sir Roger Wimbledon deals combat damage to a player, you may put an exiled creature card you own into your hand.

[+1]: Create a 1/1 blue Bird creature token with flying and haste.
[–1]: Creatures you control with flying get +1/+0 and gain vigilance until end of turn.
[–6]: Search your library for any number of creatures with flying and put them onto the battlefield. Shuffle your library.