Mana Confluence

{T}, Pay 1 life: Add one mana of any color.

Taiga

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.

Pendelhaven

{T}: Add {G}.
{T}: Target 1/1 creature gets +1/+2 until end of turn.

Virulent Sliver

All Sliver creatures have poisonous 1. (Whenever a Sliver deals combat damage to a player, that player gets a poison counter. A player with ten or more poison counters loses the game.)

Bayou

Gemhide Sliver

All Slivers have "{T}: Add one mana of any color."

Sliver Hive

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a Sliver spell.
{5}, {T}: Create a 1/1 colorless Sliver creature token. Activate only if you control a Sliver.

Tropical Island

Dregscape Sliver

Each Sliver creature card in your graveyard has unearth {2}.
Unearth {2} ({2}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Basal Sliver

All Slivers have "Sacrifice this permanent: Add {B}{B}."

Galerider Sliver

Sliver creatures you control have flying.

Cloudshredder Sliver

Sliver creatures you control have flying and haste.

Metallic Sliver

Manaweft Sliver

Sliver creatures you control have "{T}: Add one mana of any color."

Pulmonic Sliver

All Sliver creatures have flying.
All Slivers have "If this permanent would be put into a graveyard, you may put it on top of its owner's library instead."

Savannah

Dramatic Reversal

Untap all nonland permanents you control.

Misty Rainforest

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.