msem-instigator

As Aquatic Refuge enters the battlefield, you may tap an untapped creature you control. If you don't, Aquatic Refuge enters the battlefield tapped.
{T}: Add {W} or {U}.

Other creatures you control can't attack or block alone.

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.

{1}{R}: Aravant Throatcutter and up to one other target Pirate or Rogue you control each get +1/+0 until end of turn.

Equipped creature gets +2/+2.
Whenever equipped creature deals combat damage to a player, exile cards from the top of their library until they exile a nonland card. You may cast that card without paying its mana cost.
Equip {2}

Vigilance
If another creature would die, exile it instead.
At the beginning of your upkeep, return each creature card exiled with Arbiter of Endless Summer to the battlefield under its owner's control.

Flash
Flying
As long as an opponent controls more creatures than you, Arbiter of the Scales gets +2/+2 and has first strike and lifelink.

Activated abilities of artifacts cost {2} more to activate.

Whenever Arcane Metalcrafter or another Wizard you control attacks, create a 1/1 colorless Construct artifact creature token that's tapped and attacking.
Whenever a Construct you control dies, Arcane Metalcrafter deals 1 damage to each opponent.

Whenever you cast an instant or sorcery spell, you may pay {1}. If you do, choose one—
• Draw a card, then discard a card.
• Tap target creature.
• Target creature gains flying until end of turn.
• Target player mills two cards.

Counter target spell. If that spell is countered this way, until the end of your next turn the next spell you cast that shares a type with it costs {X} less to cast, where X is the countered spell's mana value.

Counter target spell unless its controller pays {2}.
Reprise {3}{U} (As you cast an instant or sorcery spell, you may exile one card with reprise from your graveyard and pay its reprise cost. If you do, add its effects to that spell.)

If you casting a noncreature spell causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Cycling {2} ({2}, Discard this card: Draw a card.)

Wanderlust — When you cast this spell, you may copy it if you control four or more differently named lands.
Exile the top two cards of your library. Until the end of your next turn, you may play those cards. Create a colorless land token named Fading Rift with “{T}, Sacrifice this land: Add one mana of any color.”

Flying
Concord — When Archangel of Accord enters the battlefield, if there are four or more card types among permanents you control, destroy all other creatures.

Flying
You may cast enchantment spells from your graveyard.
Whenever an enchantment enters the battlefield under your control, draw a card.

When Archive Guardian enters the battlefield, return target card from your graveyard to your hand.
Recite {1}{B}{G} (You may cast this creature from your graveyard for its recite cost. If you do, exile it when it enters the battlefield or if it would leave the battlefield.)

Target opponent chooses a number. When they do, choose one —
• That player discards their hand, then draws cards equal to the chosen number.
• Archivist's Torment deals damage to that player equal to the chosen number.

Whenever Archlegislator attacks, adjudicate. (Create a white Aura enchantment token with enchant creature and “Sacrifice this token: Untap enchanted creature” attached to target creature.)
{3}{R}{R}, {T}, Sacrifice an Aura: Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.

Flying, lifelink
{2}{W}{W}, Exile Archon of Sunrise from your graveyard: Create a token that's a copy of it, except it's an Aura enchantment with enchant creature and “Enchanted creature gets +4/+4 and has flying and lifelink.” Activate only as a sorcery.

Flying, vigilance
As Archon of the Accord enters the battlefield, choose a number.
Spells with mana value equal to the chosen number can't be cast.

({T}: Add {W} or {B}.)
Whenever Arctic Mine becomes tapped, you lose 1 life unless you control two or more basic lands.

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.

Create a 1/1 red and green Elemental creature token. Creatures you control get +1/+1 and gain haste until end of turn.
Orchestrate {R}{G} (You may exile this card from your hand anytime you could cast a sorcery for its orchestrate cost. When you next resolve a spell, you may cast this from exile without paying its mana cost.)