msem-instigator

Choose target creature, then flip a coin. If you win the flip, Long Shot deals 5 damage to that creature. Otherwise, return Long Shot to its owner's hand.

When Load-Bearing Behemoth dies, destroy target artifact or land.

When Living Hoard enters, create a Treasure token.
{R}, Sacrifice an artifact: Living Hoard gets +2/+0 until end of turn.

Glitch {2} (Remove one [restriction] for each time you pay the glitch cost.)
Lag Spike deals 3 damage to target [blocking] creature.

Whenever you cast a spell that targets one or more permanents you don't control, gain control of those permanents until end of turn. Untap them. They gain haste until end of turn.

Double strike, menace, trample
At the beginning of your end step, sacrifice Juddering Mishap unless you've cast a spell with no creature types this turn. (Noncreature spells have no creature types.)

Trample
{1}{R}: Each attacking creature you control with trample gets +1/+0 until end of turn.

Glitch {2} (Remove one [restriction] for each time you pay the glitch cost.)
Improbable Aim deals damage to target creature or planeswalker equal to the number of [instant and sorcery] cards in your graveyard.

Equipped creature gets +3/+1 and has haste.
Equip Soldier or Warrior {1}
Equip {4}

(Add a quest counter as this enters. Sacrifice after 5.)
Whenever you cast a spell, add a quest counter.
Discard a card. If you do, draw a card.
Target opponent discards a card, then draws a card. If they discarded a card with greater mana value than each spell you control, remove a quest counter from Gambler's Tournament.
Discard your hand, then draw seven cards.

Flooding Magma deals 2 damage to each creature except for equipped creatures you control.

Glitch {2} (Remove one [restriction] for each time you pay the glitch cost.)
Until end of turn, target creature you control gets +3/+0 and gains first strike and haste. [Sacrifice it at the beginning of the next end step.]

Equipped creature gets +1/+0 and has menace.
Equip {1}

Engulf in Flames deals 1 damage to target player and each of up to three target creatures that player controls. Those creatures can't block this turn.

Whenever Bold Vanquisher attacks, upgrade it. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• Trample

Target creature you don't control fights target creature you control, then fights up to one other target creature you don't control.

Whenever Arena Challenger deals damage to a creature, upgrade it. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• First strike
• Prowess

Deathtouch

All creatures get -2/-2 until end of turn. Add {B}{B}.

When Undying Lich dies, create a 6/3 black Zombie Horror creature token with menace and “When this creature dies, create an 8/5 black Elder Demon Horror creature token with flying, deathtouch, and menace.”

Choose X. You may choose the same mode more than once.
• Each opponent loses 3 life and you gain 3 life.
• Each opponent sacrifices a nonland permanent and you create a Treasure token.
• Each opponent discards a card and you draw a card.

{2}{B}, Exile a card from your graveyard: Tomb Creeper gets +2/+2 until end of turn.

Equipped creature gets +2/+0 and has deathtouch.
Equip Rogue or Assassin {1}
Equip {3}

[+2]: Up to one target creature gets -1/-1 until your next turn. Tap it. You may remove all counters from it.
[–2]: Destroy target creature with no counters on it.
[–10]: Each opponent's life total becomes equal to the number of creatures they control.

When Shambling Retinue dies, create a 2/2 black Zombie creature token.