msem-instigator

Scry 2, then draw two cards.
You have no maximum hand size for the rest of the game.

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Equipped creature has hexproof and distorted. (It can be blocked by tapped creatures but not untapped creatures.)
Equip {1}

When Seeker's Guardian enters, reveal the top card of your library.

Seismic Strike deals damage to target creature equal to the number of Mountains you control.

Another target player reveals their hand. You may choose an instant or sorcery card from it and cast it without paying its mana cost.
Fuse (You may cast one or both halves of this card from your hand.)

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever a +1/+1 counter is put on Sejiri Skyhunter, it gains flying until end of turn.

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

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.”

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.

Target player discards two cards. If a creature you control died this turn, that player loses 2 life.

Untap all permanents you control during each other player's untap step.

When Sentient Contraption enters, create a 1/1 colorless Thopter artifact creature token with flying.

Soldiercycling {1}{W}, Wizardcycling {1}{U}, Zombiecycling {1}{B}, Warriorcycling {1}{R}, Elfcycling {1}{G} ({1}{G}, Discard this card: Search your library for an Elf card, reveal it, and put it into your hand, then shuffle.)
Sentinel of Latter Days is every creature type as long as it's in your library.

Equipped creature has vigilance and reach.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Deathtouch, menace
As long as you control another Knight creature, Ser Joffrey, Plague of Nines and other Knight creatures you control have first strike.

Trample
Ser Malcomn's power and toughness are each equal to the number of nonbasic lands your opponents control.

Sera of Coppercove attacks each combat if able.
Whenever Sera of Coppercove attacks, it fights target creature you don't control.
{1}{R}{G}: Sera of Coppercove gets +3/+3 until end of turn.

Equipped creature gets +2/+0 and can't block.
Equip {1}

Draw two cards. If you control an Angel, draw three cards instead.

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.

Noncreature spells your opponents cast cost {1} more to cast.

[+1]: Create two 1/1 white Warrior creature tokens. You gain 2 life.
[–2]: Destroy each creature with the greatest power or tied for the greatest power among creatures on the battlefield.
[–5]: Creatures you control get +X/+X and gain lifelink until end of turn, where X is the number of creatures you control.

Enchant player
At the beginning of enchanted player's upkeep, that player creates a 1/1 white Soldier creature token.