The Tabernacle at Pendrell Vale

All creatures have "At the beginning of your upkeep, destroy this creature unless you pay {1}."

Cavern of Souls

As Cavern of Souls enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Mox Jet

Mox Pearl

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Mox Amber

{T}: Add one mana of any color among legendary creatures and planeswalkers you control.

Synapse Sliver

Whenever a Sliver deals combat damage to a player, its controller may draw a card.

First Sliver's Chosen

Sliver creatures you control have exalted. (Whenever a creature you control attacks alone, it gets +1/+1 until end of turn for each instance of exalted among permanents you control.)

Horned Sliver

Ward Sliver

As Ward Sliver enters, choose a color.
All Slivers have protection from the chosen color.

Two-Headed Sliver

All Sliver creatures have menace. (They can't be blocked except by two or more creatures.)