Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Leveler

When Leveler enters, exile all cards from your library.

Ebonblade Reaper

Whenever Ebonblade Reaper attacks, you lose half your life, rounded up.
Whenever Ebonblade Reaper deals combat damage to a player, that player loses half their life, rounded up.
Morph {3}{B}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Vile Entomber

Deathtouch
When Vile Entomber enters, search your library for a card, put that card into your graveyard, then shuffle.

Sol Ring

Inverter of Truth

Devoid (This card has no color.)
Flying
When Inverter of Truth enters, exile all cards from your library face down, then shuffle all cards from your graveyard into your library.

Archfiend of the Dross

Flying
Archfiend of the Dross enters with four oil counters on it.
At the beginning of your upkeep, remove an oil counter from Archfiend of the Dross. Then if it has no oil counters on it, you lose the game.
Whenever a creature an opponent controls dies, its controller loses 2 life.

The Beamtown Bullies

Vigilance, haste
{T}: Target opponent whose turn it is puts target nonlegendary creature card from your graveyard onto the battlefield under their control. It gains haste. Goad it. At the beginning of the next end step, exile it. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Entomb

Search your library for a card, put that card into your graveyard, then shuffle.

Eater of Days

Flying, trample
When Eater of Days enters, you skip your next two turns.

Buried Alive

Search your library for up to three creature cards, put them into your graveyard, then shuffle.