msem-instigator

When Prismatic Basilisk enters, you may search your library for a permanent card with mana value 1 or less, reveal it, put it into your hand, then shuffle.
{2/W}{2/U}{2/B}{2/R}{2/G}: Prismatic Basilisk gets +5/+5 and gains flying until end of turn.

When Prophetic Prismite enters, draw a card.
{2}: Add one mana of any color.

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

{T}: Add {C}.
{1}: Risti Workshop becomes a creature in addition to its other types until end of turn.
When Risti Workshop deals combat damage to an opponent, you may sacrifice it. If you do, search your library for a basic land card, put it onto the battlefield, then shuffle.

Rosesworn Knight gets +1/+1 as long as it's embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

When Runed Servitor dies, each player draws a card.

When Scabrous Automaton dies, draw a card, then add {C}{C}. Until end of turn, you don't lose this mana as steps and phases end.

Crew 1 (Tap any number of creatures you control with total power 1 or greater: This Vehicle becomes an artifact creature until end of turn.)
Whenever Scavengermobile deals combat damage to a player, choose land or nonland, then rediscover a card of that kind. (Look at the top card of your library. You may reveal it and put it into your hand if it's a card of the chosen type. Otherwise, put it back or into your graveyard.)

Scrap, the Second Myr has all activated abilities of other artifact creatures you control.

Other artifacts you control have ward {1}.
Overcast — Whenever you cast an artifact creature spell, if {C} was spent to cast it, it enters with an additional +1/+1 counter on it.

As Straw Simulacrum enters, choose a creature type.
Straw Simulacrum is the chosen creature type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

When Tempered Ankulim enters, choose one —
• You gain 2 life.
• Each opponent loses 2 life.

Whenever The Winged Steed attacks, create a 4/4 red Dragon creature token with flying that's tapped and attacking. Exile that token at end of combat.
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.)

You may exile a land card from your hand rather than pay this spell's mana cost.

Treacherous Oasis enters tapped.
{T}: Add {U} or {B}.
{2}{U}{B}: Until end of turn, Treacherous Oasis becomes a Crocodile creature in addition to its other types. It can't be blocked this turn.
Scavenge {1}{U}{B}

Untap all other artifacts you control during each other player's untap step.
{T}: Untap another target permanent.

Hexproof
As long as an opponent controls a permanent you own, Vault Sentinel gets +4/+4.

Advance {3} (Cast this for {3} to advance it as it enters. {3}: Advance this as a sorcery.)
Whenever Wastes Scrambler advances, put your choice of a +1/+1, first strike, menace, trample, or vigilance counter on it. If {R}{W}{B} was spent to advance it, repeat this process twice.
Crew 1

Vigilance
When Akrasan Sentry enters, untap target creature.

As long as you have 25 or more life, Alia's Enforcer gets +2/+2 and gains flying.
Whenever an artifact or enchantment you control enters, you gain 1 life.

When Arcor-Staff Adherent enters, you may remove all -1/-1 counters from target creature.

When Armored Valiant enters, creatures you control get +1/+1 until end of turn.

Whenever two or more creatures an opponent controls attack, adjudicate. (Create a white Aura enchantment token with enchant creature and “Sacrifice this token: Untap enchanted creature” attached to target creature.)
Enchanted creatures you control get +0/+2.

When Arms Merchant enters, look at the top four cards of your library. You may reveal an artifact card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Flash
When Artisan of Marrow enters, exile another target creature until Artisan of Marrow leaves the battlefield.