Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Dark Ritual

Sol Ring

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Esper Sentinel

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is Esper Sentinel's power.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Arcane Signet

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

Phyrexian Tower

{T}: Add {C}.
{T}, Sacrifice a creature: Add {B}{B}.

Teysa Karlov

If a creature dying causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Creature tokens you control have vigilance and lifelink.