msem-instigator

At the beginning of combat on your turn, choose one that hasn't been chosen —
• Creatures you control get +1/+1 and gain flying until end of turn.
• Creatures you control get +1/+1 and gain lifelink until end of turn.
• Creatures you control get +3/+3 until end of turn.
• Sacrifice each creature you control.

As Protean Jar enters, choose a creature type.
Each creature you control of the chosen type enters with an additional +1/+1 counter on it.
{2}: If Protean Jar isn't a creature, it becomes a copy of target creature you control of the chosen type, except it has Protean Jar's other abilities. Activate only as a sorcery.

Vigilance, haste
At the beginning of each player's upkeep, if that player has the lowest life total or is tied for the lowest life total, they gain control of Protector of the Innocent.

{T}: Add one mana of any color.
{4}, {T}, Sacrifice Prototype Engine: Put four -1/-1 counters on target creature.

{1}: Prototype Rice Thresher gets +1/-1 or -1/+1 until end of turn.

As Publishing Press enters, you may exile a nonland card with mana value 2 or less from your hand.
At the beginning of your upkeep, you may cast a copy of the exiled card without paying its mana cost if the spell's mana value is 2 or less.

{3}, {T}, Sacrifice Punja Stick Trap: Punja Stick Trap deals 2 damage to target creature. Tap it.

Equipped creature gets +2/+0.
Equipped creature has first strike as long as it's attacking.
Equip {2}

Art of war — At the beginning of your end step, if Raiun Bay Junk dealt damage to an opponent this turn, put a +1/+1 counter on it.
Tap an untapped creature you control: Raiun Bay Junk becomes an artifact creature until end of turn.

Equipped creature gets +1/+1 for each Equipment attached to it.
Whenever an Equipment you control enters, attach it to equipped creature.
Equip {2}

Equipped creature has “Whenever this creature attacks, untap each other creature you control.”
Equip {3}

Defender, reach
Bulwark — {X}, {T}: Rampart Ballista deals X damage to each opponent. X can't be greater than the number of creatures you control with toughness 4 or greater.

Equipped creature is a Flagbearer in addition to its other types.
While an opponent is choosing targets as part of casting a spell they control or activating an ability they control, that player must choose at least one Flagbearer on the battlefield if able.
Equip {5}

{T}: Add {C}.
{2}, {T}: Target creature gains haste until end of turn.

{T}: Add {C}.
{T}, Reappropriate: Add one mana of any color. (To reappropriate, exile exactly two cards from your hand and/or graveyard.)

{T}: Add {C}.
{1}, {T}: Add one mana of any color. This ability costs {1} less to activate if there are three or more colors among cards in your graveyard.

Menace
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)

When Recon Drone enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle. Then if you did, put a card from your hand on the bottom of your library.

Flash
{1}, {T}: Scry 1.

Whenever you draw a card, put a hatch counter on Reefcrown Egg.
{T}, Sacrifice Reefcrown Egg: You may put a creature card with mana value less than or equal to the number of hatch counters on Reefcrown Egg from your hand onto the battlefield.
Cycling {2} ({2}, Discard this card: Draw a card.)

When Remnant of Lost Times enters, scry 1.
{2}, Sacrifice Remnant of Lost Times: Draw a card.

{T}: Target player exiles a card from their graveyard.
{2}, Sacrifice Remnant of Past Realities: Exile each opponent's graveyard. Draw a card.

When Renegade Servitor enters, you gain 2 life and scry 1.

{T}, Sacrifice Renewal Grove: Search your library for a basic land card, put it onto the battlefield, then shuffle. If Renewal Grove entered since your last upkeep, that land doesn't untap during your next untap step.

When Repurposed Custodian enters, shuffle any number of target cards from graveyards into their owner's libraries.