Cavern of Souls

As Cavern of Souls enters the battlefield, choose a creature type. {T}: Add {1} to your mana pool. {T}: Add one mana of any color to your mana pool. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Chalice of the Void

Chalice of the Void enters the battlefield with X charge counters on it. Whenever a player casts a spell with converted mana cost equal to the number of charge counters on Chalice of the Void, counter that spell.

Blinkmoth Nexus

{T}: Add {1} to your mana pool. {1}: Blinkmoth Nexus becomes a 1/1 Blinkmoth artifact creature with flying until end of turn. It's still a land. {1}, {T}: Target Blinkmoth creature gets +1/+1 until end of turn.

Spellskite

{U/P}: Change a target of target spell or ability to Spellskite. ({U/P} can be paid with either {U} or 2 life.)

Simian Spirit Guide

Remove Simian Spirit Guide in your hand from the game: Add {R} to your mana pool.

Urborg, Tomb of Yawgmoth

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

Umezawa's Jitte

Whenever equipped creature deals combat damage, put two charge counters on Umezawa's Jitte. Remove a charge counter from Umezawa's Jitte: Choose one — Equipped creature gets +2/+2 until end of turn; or target creature gets -1/-1 until end of turn; or you gain 2 life. Equip {2}

Dismember

({B/P} can be paid with either {B} or 2 life.) Target creature gets -5/-5 until end of turn.

Eldrazi Temple

{T}: Add {1} to your mana pool. {T}: Add {2} to your mana pool. Spend this mana only to cast colorless Eldrazi spells or activate abilities of colorless Eldrazi.

Ratchet Bomb

{T}: Put a charge counter on Ratchet Bomb. {T}, Sacrifice Ratchet Bomb: Destroy each nonland permanent with converted mana cost equal to the number of charge counters on Ratchet Bomb.

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.

Endless One

Oblivion Sower

Ghost Quarter

Eldrazi Mimic

Endbringer

Matter Reshaper

Reality Smasher

Thought-Knot Seer

Warping Wail

Wastes

Eye of Ugin

Leyline of the Void

If Leyline of the Void is in your opening hand, you may begin the game with it on the battlefield. If a card would be put into an opponent's graveyard from anywhere, exile it instead.