Virus Beetle

When Virus Beetle enters, each opponent discards a card.

Mirkwood Bats

Flying
Whenever you create or sacrifice a token, each opponent loses 1 life.

Deep-Cavern Bat

Flying, lifelink
When Deep-Cavern Bat enters, look at target opponent's hand. You may exile a nonland card from it until Deep-Cavern Bat leaves the battlefield.

Geth's Grimoire

Whenever an opponent discards a card, you may draw a card.

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad, the Grim deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

Arcane Signet

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

Swamp

Burglar Rat

When this creature enters, each opponent discards a card.

Temple of the Dead

(Transforms from Aclazotz, Deepest Betrayal.)
{T}: Add {B}.
{2}{B}, {T}: Transform Temple of the Dead. Activate only if a player has one or fewer cards in hand and only as a sorcery.

Aclazotz, Deepest Betrayal

Flying, lifelink
Whenever Aclazotz attacks, each opponent discards a card. For each opponent who can't, you draw a card.
Whenever an opponent discards a land card, create a 1/1 black Bat creature token with flying.
When Aclazotz dies, return it to the battlefield tapped and transformed under its owner's control.

Aclazotz, Deepest Betrayal // Temple of the Dead

Bitter Triumph

As an additional cost to cast this spell, discard a card or pay 3 life.
Destroy target creature or planeswalker.

Bloodletter of Aclazotz

Flying
If an opponent would lose life during your turn, they lose twice that much life instead. (Damage causes loss of life.)

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Nezumi Informant

When Nezumi Informant enters, each opponent discards a card.

Containment Construct

Whenever you discard a card, you may exile that card from your graveyard. If you do, you may play that card this turn.