msem-instigator

At the beginning of your upkeep, you may pay {1}{G/U}. If you do, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)
At the beginning of your end step, you may pay {1}{G/U}. If you do, populate. (Create a token that's a copy of a creature token you control.)

Flying, lifelink
Improve {1}{W/B} ({1}{W/B}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Once each turn, when you gain life, you may have each opponent lose 2 life.

This spell costs {1} less to cast for each enchantment you control.
Flying, lifelink, trample
Disturb {6}{B}{B}. That spell costs {1} less to cast for each enchantment you control. (You may cast this card from your graveyard transformed for its disturb cost.)

You may choose not to untap Arden, Mirrormage during your untap step.
Whenever Arden becomes untapped or leaves the battlefield, sacrifice all tokens created with it.
{3}{U}, {T}: Create a token that's a copy of another creature on the battlefield.

[+1]: Search your library for a land card, put it onto the battlefield, untap it, then shuffle. Sacrifice a land.
[–2]: Destroy target noncreature permanent. Its controller may search their library for a basic land card, put that card onto the battlefield, then shuffle.
[–6]: Return any number of land cards from your graveyard to the battlefield and untap them. They become 3/3 creatures with haste in addition to their other types.

[+1]: Untap target land.
[–1]: Exile the top card of your library. You may play that card until end of turn. If a land card is exiled this way, you gain 2 life.
[–7]: Untap each land you control. Lands you control become 3/3 Elemental creatures with haste until end of turn. They're still lands.

{U}{B}, {T}: Draw a card, then each player exiles the top card of their library. Then if a player owns two or more cards exiled with Arina, Volarian Explorer, exile her, then return her to the battlefield transformed under her owner's control.

Menace, haste
As long as Arleigh, Spellblade Prodigy is tapped, the first spell you cast during each other player's turn costs {U/R} less to cast. This effect reduces only the amount of colored mana you pay. (For example, if you cast a spell with mana cost {1}{R}, it costs {1} to cast.)

Once during each of your turns, when a card is put into a graveyard from anywhere, you may cast it. You may spend mana of any color to cast that spell.
When Arroyo, Infinitely Branching is put into your graveyard from anywhere, you may cast it.

{1}{G/W}: Put a +1/+1 counter on Artful Chari.
Whenever you cast an instant or sorcery spell, you may remove a number of +1/+1 counters from Chari equal to that spell's mana value. If you do, copy that spell, and you may choose new targets for the copy.

Flying
At the beginning of your upkeep, you may create a token that is a copy of target Aura you control and attach it to target permanent or player it could enchant.
{2}, Sacrifice an Aura: Artiaburz gains indestructible and hexproof until end of turn.

When Artian, Phyrexian Architect enters, search your library for a land card, put it onto the battlefield, then shuffle.
At the beginning of your upkeep, put a corruption counter on a land you control. Then create a 1/1 colorless Phyrexian artifact creature token for each land you control with a corruption counter on it.

Hexproof
At the beginning of your upkeep, put a card from your hand on top of your library. You may shuffle.
{1}: Look at the top three cards of your library, then put them back in any order.
{2}{U}: Draw a card.

First mate — Each land card in your starting deck has a different name. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Lifelink, vigilance
Asabeth of the Intrepid's power and toughness are each equal to the number of lands you control.

First strike, vigilance
Whenever Asamund, Queen of Yroncaster deals combat damage to a player, choose a number. That player can't cast noncreature spells with mana value equal to the chosen number until the end of your next turn.

First mate — Twelve or more cards in your starting deck are Dragons or have “Dragon” in their printed rules text. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Dragon spells you cast cost {1} less to cast.
Whenever Ashe attacks, it deals X damage to any target, where X is the number of Dragons you control.

When Astrid, Disgruntled Princess enters, destroy target creature with mana value less than or equal to the number of Warriors you control.

Once each turn, when Atal, the Shroudmaker enters or you attack with one or more Horrors, you may create two tapped 1/1 colorless Human creature tokens. If Atal isn't a token, creatures you control gain flying until end of turn.
{2}{W}{W}, Discard Atal: Create a token that's a copy of Atal, the Shroudmaker, except it's 4/4 and isn't legendary. Activate only as a sorcery.

Indestructible
As long as your devotion to white and black is less than seven, Athreos isn't a creature.
Other creatures you control have lifelink.
Each player and cards in graveyards can't be the targets of spells or abilities your opponents control.

Menace, haste
At the beginning of combat on your turn, gain control of up to two target noncreature, nonland permanents your opponents control until end of turn. Untap those permanents. You may attach any number of Equipment among them to creatures you control until end of turn. (They unattach at end of turn.)

This spell can't be countered.
Flying
When Aunor, Dragonsire or another Dragon you control enters, untap target land. That land becomes a 5/5 Dragon creature with flying and haste in addition to its other types.

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)
During each of your turns, you may cast an instant or sorcery spell from your graveyard. If that spell would be put into your graveyard, exile it instead.
Whenever Aurora, Soulweaver attacks, untap any number of target creatures.

This spell can't be countered.
When Auros enters, it deals damage to any target equal to your devotion to red. (Each {R} in the mana costs of permanents you control counts toward your devotion to red.)
{R}, Sacrifice Auros, Discard your hand: Draw three cards.

Flying
Spirited (When this creature enters, you may activate one of its activated abilities without paying its costs.)
{3}{U/B}{U/B}: Look at the top card of target opponent's library, then exile it face down. You may play that card for as long as it remains exiled, and you may spend mana as though it were mana of any type to cast that spell.

Whenever you gain life, amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control one, create a 0/0 black Zombie Army creature token first.)
If you would gain life except for the first time each turn, instead each opponent loses 1 life. (If multiple sources would cause you to gain life at the same time, choose one to be first.)