Elvish Spirit Guide

If Elvish Spirit Guide is in your hand, you may remove it from the game to add {G} to your mana pool. Play this ability as an interrupt.

Dark Depths

Dark Depths comes into play with ten ice counters on it. {3}: Remove an ice counter from Dark Depths. When Dark Depths has no ice counters on it, sacrifice it. If you do, put an indestructible legendary 20/20 black Avatar creature token with flying named Marit Lage into play.

Thespian's Stage

{T}: Add {1} to your mana pool. {2}, {T}: Thespian's Stage becomes a copy of target land and gains this ability.

Snow-Covered Forest

{T}: Add {G} to your mana pool.

Snow-Covered Swamp

{T}: Add {B} to your mana pool.

Urborg, Tomb of Yawgmoth

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

Sylvan Library

You may draw two extra cards during your draw phase. If you do so, put two of the cards drawn this turn back on top of your library (in any order) or pay 4 life per card not replaced. Effects that prevent or redirect damage cannot be used to counter this loss of life.

Not of This World

Counter target spell or ability that targets a permanent you control. Not of This World costs {7} less to cast if it targets a spell or ability that targets a creature you control with power 7 or greater.

Lotus Petal

Sacrifice Lotus Petal: Add one mana of any color to your mana pool. Play this ability as a mana source.

Pithing Needle

As Pithing Needle comes into play, name a card. Activated abilities of sources with the chosen name can't be played unless they're mana abilities.

Thoughtseize

Target player reveals his or her hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Bayou

Counts as both swamp and forest and is affected by spells that affect either. Tap to add either {B} or {G} to your mana pool.

Crop Rotation

At the time you play Crop Rotation, sacrifice a land. Search your library for a land card and put that land into play. Shuffle your library afterwards.

Bojuka Bog

Bojuka Bog enters the battlefield tapped. When Bojuka Bog enters the battlefield, exile all cards from target player's graveyard. {T}: Add {B} to your mana pool.

Sejiri Steppe

Sejiri Steppe enters the battlefield tapped. When Sejiri Steppe enters the battlefield, target creature you control gains protection from the color of your choice until end of turn. {T}: Add {W} to your mana pool.

Vampire Hexmage

First strike Sacrifice Vampire Hexmage: Remove all counters from target permanent.

Expedition Map

{2}, {T}, Sacrifice Expedition Map: Search your library for a land card, reveal it, and put it into your hand. Then shuffle your library.

Verdant Catacombs

Sylvan Scrying

Ghost Quarter

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.