msem-instigator

{T}: Add {R} or {W}.
{R}{W}, {T}: Target creature gains first strike and haste 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 the battlefield, reveal the top card of your library.

Equipped creature gets +1/+1.
At the beginning of your end step, if you don't control a creature, create a 1/1 white Human creature token and attach Seeking Sword to it.
Equip {1}

{3}, {T}: Scry 3.
{5}, {T}: Fateseal 3.
{7}, {T}: Draw two cards.

{T}: Add {C}.
{7}, {T}: Create a 2/2 colorless Spirit creature token.

Equipped creature gets +1/+0 for each colorless creature you control.
Equip {1}

Concord — This spell costs {4} less to cast if there are four or more card types among permanents you control.
Vigilance, trample, lifelink, haste

Equipped creatures you control get +1/+1.
You may activate equip abilities any time you could cast an instant.
Equip {2}

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

When Sentient Contraption enters the battlefield, 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.)

{T}: Add {C}.
{T}, Reappropriate: Add {U} or {B}. (Exile exactly two cards from your hand and/or graveyard.)

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

Serene Chapel enters the battlefield tapped unless you control a basic Plains.
{T}: Add {W}.
{1}{W}{W}: Until end of turn, Serene Chapel becomes a 2/1 white Spirit Cleric creature with flying and “Whenever this creature attacks, you may exile target card from a graveyard.” It's still a land.

{T}: Add {G} or {U}. You lose 1 life unless you have less life than an opponent.

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

Equipped creature gets +1/+1 and has deathtouch.
{1}: Serpent Staff becomes a 1/1 green Snake creature with deathtouch and loses all other abilities until end of turn.
Equip {3}

Serpentine Woods enters the battlefield tapped.
{T}: Add {B} or {G}.
{2}{B}{G}, {T}, Sacrifice Serpentine Woods: Draw a card.

When Servant of Armageddon dies, destroy all creatures.

When Servant of Precursors enters the battlefield, you gain 4 life and draw a card.

Menace
Servitor Vanguard gets +X/+X, where X is the number of other artifacts you control.

Equipped creature gets +2/+2 and has ward {2} and “Whenever this creature attacks, draw a card, then you may put a land card from your hand onto the battlefield.”
Equip {2}

{T}: Add {C}.
{5}{R}{G}, {T}: Transform Settled Satrapy.