msem-instigator

{T}: Look at the top and bottom card of your library. Put up to one on top of your library and the rest on the bottom in any order.
{2}: Mill a card.

{5}, {T}, Sacrifice Mennin Jar: Destroy target permanent. Its controller creates a 1/1 black Goblin creature token.

Activated abilities you control cost up to {1} less to activate. This effect can't reduce the amount of mana an ability costs to activate to less than one mana.

{T}: Add {C}.
Satrapies you control enter untapped.

{T}, Sacrifice Merchant's District: Search your library for an Island or Mountain card and put it onto the battlefield tapped, then shuffle.

At the beginning of your upkeep, draw a card.
At the beginning of your end step, discard a card.

Equipped creature gets +0/+4.
Equip {2}

Whenever another artifact you control enters, put a +1/+1 counter on Metalwork Machinist.

When Mettalia's Forward enters, you may salvage a card. (Exile one from your graveyard until this creature leaves the battlefield. Whenever this creature deals combat damage to a player, put a card it salvaged into your hand.)

Mettalia is all colors.
Mettalia has protection from each color among cards she's salvaged in exile.
When Mettalia enters, for each color, you may salvage a nonlegendary card of that color. (Exile one from your graveyard until this creature leaves the battlefield. Whenever this creature deals combat damage to a player, put a card it salvaged into your hand.)

({T}: Add {B}.)
As Midnight Gate enters, you may pay 1 life. If you don't, Midnight Gate enters tapped.
Basic lands you control have “{T}: Add {B}.”

{T}: Add {C}.
{3}: Mill two cards, then return Midnight Keep from your graveyard to the battlefield tapped.

When Mighty Totem enters, scry 1.
{1}{G}, Sacrifice Mighty Totem: Target creature gets +3/+3 until end of turn.

MiliCore Barracks enters tapped.
{T}: Add {B} or {R}.
{B}{R}, {T}: Create a Function token with “Deathtouch.” Activate only if an opponent lost life this turn. (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

Mind Palace enters tapped.
{T}: Add {U} or {B}.
When Mind Palace enters, you may put a loyalty counter on a planeswalker you control.

As Mind-Mute enters, choose a card name.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.
{5}: Return Mind-Mute to its owner's hand.

Creatures with power greater than the number of cards in their controller's hand can't attack.

When Mindwave Rod enters, attach it to target creature you control.
Equipped creature gets +1/+1 and has “Whenever this creature deals combat damage to a player, draw a card.”
Equip {2}

{2}{R}, Sacrifice Minefield Bomber: It deals 2 damage to any target.
Cycling {2/R} ({2/R}, Discard this card: Draw a card.)

Flying
When Mineral Retriever enters, create a Treasure token.

Equipped creature gets +1/+1. If it's a token, it gets +3/+3 instead.
Equip {2}

At the beginning of your upkeep, choose another planeswalker you control. You may activate that planeswalker's loyalty abilities twice this turn rather than only once.
[+2]: You may put a land card from your hand onto the battlefield. If you don't, each player draws a card.
[–2]: Exile target permanent. Return it to the battlefield under its owner's control at the beginning of the next end step.
[–7]: For each land on the battlefield, add one mana of any type that land could produce.

Puzzlebox (Begin the game with this and another card you own from outside the game in the command zone, locked. That card is face down until you unlock this.)
When the fourth spell of a turn is cast, you may unlock Mirror Cipher. If the revealed card is an instant or sorcery card, cast it without paying its mana cost and copy it. You may choose new targets for the copy.

Whenever equipped creature blocks or becomes blocked by a creature, you may have equipped creature become a copy of that creature until end of turn.
Equip {1}