Kasmina, Sage of Owls
Planeswalker - Kasmina
Whenever a Bird creature enters the battlefield under your control, look at the top card of target player's library. You may put that card on the bottom of that library.
Create a 1/1 blue Bird creature token with Flying.
Choose target opponent. You control that player during their next turn.

Duel with Seconds —
Enchantment — Aura (C)
Enchant creature you control
Exploit (When this aura enters the battlefield, you may sacrifice a creature.)
Enchanted creature gets +2/-1.
Whenever you exploit a creature, you may have enchanted creature fight target creature an opponent controls. If the exploited creature was a token, enchanted creature gets +2/+2 until end of turn.
Montieres lords frequently challenge others in duels, but the codes involving seconds means that only those in lesser classes ever pay for any perceived insult.

Wait so what happens if you exploit the enchanted creature and it is a token?

Cursed Idol of Virago
Artifact (U)
~ enters the battlefield tapped.
Exploit
Whenever you exploit a creature, untap ~.
: Target opponent loses 1 life.

Enchanted creature can't fight anything, because it's dead, so I guess you just waste a card.

State Mourning —
Sorcery (R)
Commander offering (You may cast this card any time you could cast an instant by sacrificing your commander and paying the difference in mana costs between this and the sacrificed card. Mana cost includes color.)
Destroy target creature or planeswalker. If if was your opponent's commander, end the turn.
Marchesa's funeral was not a pause in the plotting but an excuse for further backstabbing.

End
Sorcery (M)
Exile target planeswalker and each other planeswalker that shares a type with it. Then, search each players' hands, graveyards, and libraries for any number of cards with that type and exile them. Each player shuffles their library.
"We will try to remember you."

Nivmagus Refinement
Instant (c)
~ is red.
Add .
Replicate .
"Pure magical energy, while extremely powerful, is also rare and volatile, and thus often needs to be derived from diluted sources. Of course, the Izzet League's methods are quite primitive by our standards . . . " - Vannifar.

Halo-Rush Dealer
Creature — Devil Citizen (U)
Haste
Alliance — Whenever another creature enters the battlefield under your control, you may discard a card. If you do, draw a card.
2/2

Lord-Eater
Legendary Creature - Giant (R)
Haste
Whenever ~ deals combat damage to a creature, exile that creature at end of combat until ~ leaves the battlefield.
[4/4]

Risk It All

Instant {MR}
For each permanent, flip a coin. If you win the flip, you may choose to exile that permanent. Otherwise, an opponent chooses whether or not to exile it.

Triumphant Roar
Sorcery (C)
Target creature you control fights target creature you don't control. If the creature you control dealt excess damage this way, put a +1/+1 counter on it.

Spore Fruition

Sorcery {U}
All +1/+1 counters become spore counters. Until end of turn, creatures gain "Remove three spore counters from this creature: create a 1/1 green saproling creature token."

Defend the Brood
Sorcery (R)
Target creature you control with mana value X or less fights each creature you don't control.

Renew
Sorcery (M)
Choose target card in a graveyard. Return all cards with that card's name in your graveyard to your hand. Exile all cards with that card's name in each other player's graveyard. You may play each card exiled this way as long as it's exiled.
Exile Renew.

Silent Librarian

Creature - Spirit Advisor {C}
Flying
Sacrifice Silent Librarian: Spells cost more to cast this turn.
"Ssssh."
0/3

Lvev Mandate
Enchantment (U)
As ~ enters the battlefield, name a nonland card.
When ~ enters the battlefield, return each nonland permanent with the chosen name to its owner's hand.
Players can't cast spells with the chosen name.

Lavinia, Grand Arbiter Pro Tem
Legendary Creature — Human Soldier (R)
At the beginning of each opponent's upkeep, they may choose Sova, Jelenn, or Lyev. (This choice replaces the last one.)

• Sova — Spells opponents cast cost more to cast.
• Jelenn — If an opponent would draw a card, you and that player each draws a card instead.
• Lyev — Whenever one or more creatures attack an opponent, untap one of them and it can't be blocked this turn.

4/4

Align the Constellations —
Enchantment — Saga (M)
Precis (This saga enters the battlefield with an additional lore counter for each mana greater than two you spent to cast it. Each chapter ability triggers separately.)
I, II, III — Exile another target permanent until ¬ leaves the battlefield.
IV — Whenever a permanent enters the battlefield from exile this turn, draw a card.

Mistmeadow Sentry
Creature - Kithkin Soldier (C)
~ enters the battlefield with a Vigilance counter if was spent to cast it and a Flying counter if was spent to cast it.
The dangers of Shadowmoor demand that a Kithkin guard dedicate themselves to watching their people, or at least know enough about Fey magic to avoid confrontationall together.
[1/1]

Obscura Conspiracist
Creature — Cephalid Rogue (U)
When Obscura Conspiracist enters the battlefield, it connives.
When Obscura Conspiracist dies, target creature you control connives.
1/2

Letter of Marque —
Artifact (R)
Whenever you're attacked, at end of combat defending player draws two cards if more attacking creatures they controlled were blocked than were unblocked, each of you draws a card if the same number of attacking creatures were blocked and unblocked, and attacking player draws two cards if more attacking creatures were unblocked than were blocked.
Delivery (: Exile this from your hand face-down under target creature as a sorcery. The next time that creature deals combat damage to a player, you may reveal this. If you do, that player plays this card without paying its mana cost.)
Armed with the Regent's letters of marque, privateers could legally pillage ports and their vessels — though the defenders often took as much loot as they lost.