msem-instigator

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.

{2}, Sacrifice Research Aquarium: Draw a card.
When Research Aquarium is put into a graveyard from the battlefield, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

When Restless Explorer enters, search your library for a land card, reveal it, put it into your hand, then shuffle.

Restored Automaton enters with X +1/+1 counters on it.
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

(Transforms from Ruined Theater.)
{T}: Add one mana of any color.

{T}: Add {C}.
{3}, Exile Resurgent Oasis from your graveyard: Choose a basic land type. Create a tapped colorless land token that's a Desert and the chosen basic land type.

{T}, Sacrifice Rickety Guildhall: Search your library for a Forest or Island card and put it onto the battlefield tapped, then shuffle.