msem-instigator

Whenever you cast an instant or sorcery spell, you may have Xenocrata's Fleet become a 4/4 Ship artifact creature with haste until end of turn.
Whenever Xenocrata's Fleet deals combat damage to an opponent, create that many 1/1 red Warrior creature tokens.

[+2]: Tap target permanent. It doesn't untap during its controller's next untap step.
[–3]: Xenocrata, Reality Breaker deals 3 damage to each creature and each other planeswalker.
[–10]: Draw seven cards. You get an emblem with “Whenever you cast an instant or sorcery spell, untap all permanents you control.”

Whenever you cast an instant or sorcery spell, put a loyalty counter on Xenocrata and tap up to one target permanent.
[0]: Each opponent can't untap more than three permanents during their next untap step.
[–3]: Xenocrata deals 6 damage divided as you choose among any number of target creatures and/or planeswalkers.
[–9]: Cast any number of instant and/or sorcery cards you own in exile and from your graveyard without paying their mana costs.

You may play an additional land each turn.
Whenever a player plays a land, that player draws a card.

(Choose only one work as a sorcery to add its ability.)
When Xie'e Amphitheatre enters, search your library for a card and exile it face down, then shuffle. You may cast that card on any turn you sacrificed a permanent.
{B}: Intro: Together
At the beginning of your upkeep, you lose 1 life and create a 0/1 black Cultist creature token with “{1}{B}{B}, Sacrifice three Cultists: Create a 5/5 black Demon creature token.”
{2}{B}: Finale: Alone
Whenever a Demon you control enters, each opponent loses life equal to its power and you gain that much life.

Trample, vigilance
Spells your opponents cast that target Xiejuan and Hao Lu cost {X} more to cast, where X is the number of other creatures you control.
Whenever another creature you control dies, draw a card.

Alpha (You may have this creature enter with a +1/+1 counter on it. If you do, it becomes alpha and can only attack alone.)
When Xiejuan, the Regal Beast becomes alpha, draw a card for each other creature you control.

(Transcend as a sorcery to gain that type and a +1/+1 counter.)
When Xifang Hu enters, noncreature spells cost {2} more to cast until your next turn.
{1}{W}: Demigod — Whenever a creature attacks this turn, create a 1/1 colorless Spirit creature token.
{4}{W}{W}: God — Distribute a flying, first strike, indestructible, lifelink, vigilance, and +1/+1 counter among any number of creatures you control.

Flying
Whenever a player spends one or more mana to activate an ability that isn't a mana ability, Xihuo deals 2 damage to each opponent.
{B}{R}, Pay 2 life: Xihuo gains double strike until end of turn. Activate only once each turn.

(Transcend as a sorcery to gain that type and a +1/+1 counter.)
Trample
{2}{R}: Demigod
Create a 2/1 black Spirit creature token with “This creature can't block.”
{5}{R}: God
Until end of turn, creatures you control get +1/+0 and gain haste and “When this creature dies, it deals 1 damage to any target.”

{1}, {T}, Sacrifice two or more nonland permanents: Return target creature card from your graveyard to the battlefield. If permanents with total mana value 4 or greater were sacrificed this way, draw a card.

Flash
This spell can't be countered.
When Xing, the Lucky Charm enters, draw three cards.
{U}{R}, Discard three cards: Return Xing from your graveyard to your hand.

[+1]: Put a +1/+1 counter on up to one target creature, then put your choice of a menace, deathtouch, or trample counter on it.
[0]: Target creature or Xiong planeswalker you control fights target creature you don't control.
[–1]: Target player sacrifices a permanent.

[0]: Sacrifice a creature. When you do, Xiong Mao, Survivalist deals damage to any target equal to that creature's power, then put a number of loyalty counters on Xiong Mao equal to that creature's toughness.
[–2]: Return up to two target creature cards from your graveyard to your hand.
[–6]: You get an emblem with “Whenever a creature you control dies, you may draw cards equal to its power, then you may gain life equal to its toughness.”

[+1]: Create a 1/1 red Panda Monk creature token with “{T}: Target player exiles a card from their graveyard.”
[0]: You may sacrifice a creature. If you do, search your library for a creature card and a land card, reveal them, put them into your hand, then shuffle.
[–2]: Xiong Mao deals damage to target creature or planeswalker equal to the greatest power among creatures you control and cards in your graveyard.
[–7]: Any number of players' life totals each become equal to the number of cards in their graveyard.

[+2]: Create a 3/3 red Panda creature token.
[–X]: Sacrifice a creature. If you do, search your library for a creature card with mana value less than or equal to X plus the sacrificed creature's mana value. Put that card onto the battlefield, then shuffle.
[–6]: You get an emblem with “Whenever a creature dies, this emblem deals damage equal to that creature's power to any target and you draw that many cards.”

[+1]: You may sacrifice a creature. If you do, return a creature card with lesser mana value from your graveyard to the battlefield.
[–1]: Other creatures and planeswalkers you control gain indestructible and can't have counters removed from them until your next turn.
[–X]: Exile X target cards from graveyards. Xiong Mao deals X damage to any target.

Choose one or both—
• Target creature you control gets +2/+2 until end of turn.
• Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

Ferocious — Whenever a creature with power 4 or greater you control enters, untap all lands you control.

Archive 5 (As this enters, shuffle the top five cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
Recursive — Xirix's Study has all nonrecursive abilities of all Study cards in graveyards except for their archive abilities.

You may activate loyalty abilities of Xirix, the Usurper during extra turns any time you could cast an instant.
[+1]: Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
[–2]: Destroy each nonland, non-Xirix permanent with the greatest mana value among non-Xirix permanents on the battlefield.
[–6]: Put target permanent card from a graveyard onto the battlefield under your control.

When target creature you control dies this turn, return that card to the battlefield tapped. Put two +1/+1 counters on it. It becomes renowned.

Renown 2 (When this creature deals combat damage to a player, if it isn't renowned, put two +1/+1 counters on it and it becomes renowned.)
Each creature you control with a +1/+1 counter on it has indestructible.

At the beginning of combat on your turn, you may pay {2}{R}{R}. If you do, create a 4/4 red Dragon creature token with flying and haste. Exile that token at end of combat.
Ferocious — Whenever Xiusheng of the Dragon Realm attacks, if you control a creature with power 4 or greater, Xiusheng gains double strike until end of turn.

Enchant creature
{R}: Enchanted creature gets +1/+0 until end of turn.
Ferocious — Whenever enchanted creature attacks, if you control a creature with power 4 or greater, enchanted creature gains double strike until end of turn.