msem-instigator

{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.

Trample
Whenever Arisen Tyrant attacks, mill three cards, then you may exile a card from your graveyard. You may cast a copy of the exiled card without paying its mana cost if the spell's mana value is 3 or less.
If Arisen Tyrant would die, exile it instead.

Whenever one or more creatures you control deals combat damage to a player, you may sacrifice one of them. When you do, destroy target creature defending player controls, then you and the destroyed creature's controller draw a card.

Target creature gets -3/-0 until end of turn. That creature's controller mills six 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.

Flash
When Axom enters, remove up to three counters from target permanent.
{2}{U}: Return Axom to its owner's hand.

Barren Vista enters tapped.
{T}: Add {U} or {B}.
{1}, {T}: Add one mana of any color.

When Bearer of Tormented Truths enters, look at target player's hand. You may exile a nonland card from among them. If you do, that player draws a card.
You may play cards exiled with Bearer of Tormented Truths, and you may spend mana as though it was mana of any color to cast them.

At the beginning of your end step, mill two cards. Then if ten or more cards are in your graveyard, transform Bitter Duckling.

Flash
Blind Blackguard can't block.
When Blind Blackguard enters, target player draws a card, then reveals their hand. You choose a nonland card from that player's hand, then that player puts the chosen card on the bottom of their library.

Gain control of target permanent. (Cast a copy of this spell once while this creature is on the battlefield.)

Counter target spell unless its controller discards two cards.

When Breaker of Secrets enters, each player mills three cards from each of their libraries.
Recite {U} (You may cast this creature from your graveyard for its recite cost. If you do, exile it when it enters or if it would leave the battlefield.)

{T}: Add {C}.
{1}, {T}: Add {U}{B}.

Flash
Whenever you cast your second spell each turn, put a +1/+1 counter on Brooding Replacement.

Your life total becomes 0. Until an opponent's next turn, you can't lose the game, your opponents can't win the game, and you can't gain life.
Take an extra turn after this one.
Exile Buy Time.

When Cave Eel enters, look at the top three cards of your library. Put one on top and the rest on the bottom in any order.

Cesspool Scrapper can't block.
{5}{U}, Exile Cesspool Scrapper from your graveyard: Draw two cards.

As Choked Estuary enters, you may reveal an Island or Swamp card from your hand. If you don't, Choked Estuary enters tapped.
{T}: Add {U} or {B}.

Whenever you cast a Rogue spell or a spell from exile, you may return Cobri to her owner's hand.

Each player draws a card, then target player mills X cards, where X is the number of cards players have drawn this turn.

Draw two cards. Each opponent loses 2 life and you gain 2 life.
Flashback {4}{U}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Crumbling Aqueduct enters tapped unless you control another Desert.
{T}: Add {U} or {B}.

{T}: Add {C}.
{T}, Pay 1 life: Add {U} or {B}.

Target creature gets +1/+0 until end of turn and can't be blocked this turn.
Flashback {1}{U/B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)