Uba Mask

If a player would draw a card, that player exiles that card face up instead.
Each player may play lands and cast spells from among cards they exiled with this artifact this turn.

Stomping Ground

({T}: Add {R} or {G}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Abbot of Keral Keep

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When this creature enters, exile the top card of your library. Until end of turn, you may play that card.

Boseiju, Who Endures

{T}: Add {G}.
Channel — {1}{G}, Discard this card: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

Kitsa, Otterball Elite

Vigilance
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
{T}: Draw a card, then discard a card.
{2}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy. Activate only if Kitsa's power is 3 or greater.

Hobgoblin, Mantled Marauder

Flying, haste
Whenever you discard a card, Hobgoblin gets +2/+0 until end of turn.

Stormcarved Coast

This land enters tapped unless you control two or more other lands.
{T}: Add {U} or {R}.

Balmor, Battlemage Captain

Flying
Whenever you cast an instant or sorcery spell, creatures you control get +1/+0 and gain trample until end of turn.

Steam Vents

({T}: Add {U} or {R}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Wooded Foothills

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

Bria, Riptide Rogue

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Other creatures you control have prowess. (If a creature has multiple instances of prowess, each triggers separately.)
Whenever you cast a noncreature spell, target creature you control can't be blocked this turn.

Scalding Tarn

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Gitaxian Spellstalker

Trample, ward {2}, prowess, prowess (Each instance of prowess triggers separately.)

Khenra Spellspear

Trample
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
{3}{U/P}: Transform this creature. Activate only as a sorcery. ({U/P} can be paid with either {U} or 2 life.)

Khenra Spellspear // Gitaxian Spellstalker

Spire Garden

This land enters tapped unless you have two or more opponents.
{T}: Add {R} or {G}.

Eruth, Tormented Prophet

If you would draw a card, exile the top two cards of your library instead. You may play those cards this turn.

Training Center

This land enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Frontier Bivouac

This land enters tapped.
{T}: Add {G}, {U}, or {R}.

Lotus Petal

{T}, Sacrifice this artifact: Add one mana of any color.

Lier, Disciple of the Drowned

Spells can't be countered.
Each instant and sorcery card in your graveyard has flashback. The flashback cost is equal to that card's mana cost.

Rockfall Vale

This land enters tapped unless you control two or more other lands.
{T}: Add {R} or {G}.

Flubs, the Fool

You may play an additional land on each of your turns.
Whenever you play a land or cast a spell, draw a card if you have no cards in hand. Otherwise, discard a card.

Misty Rainforest

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

Mystic Peak

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {R}.

Pinnacle Monk

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When this creature enters, return target instant or sorcery card from your graveyard to your hand.

Pinnacle Monk // Mystic Peak

Drake Hatcher

Vigilance, prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever this creature deals combat damage to a player, put that many incubation counters on it.
Remove three incubation counters from this creature: Create a 2/2 blue Drake creature token with flying.

Breeding Pool

({T}: Add {G} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Fabled Passage

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Dreamroot Cascade

This land enters tapped unless you control two or more other lands.
{T}: Add {G} or {U}.

Stormcatch Mentor

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Instant and sorcery spells you cast cost {1} less to cast.

Electro, Assaulting Battery

Flying
You don't lose unspent red mana as steps and phases end.
Whenever you cast an instant or sorcery spell, add {R}.
When Electro leaves the battlefield, you may pay {X}. When you do, he deals X damage to target player.

Ketria Triome

({T}: Add {G}, {U}, or {R}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Chameleon, Master of Disguise

You may have Chameleon enter as a copy of a creature you control, except his name is Chameleon, Master of Disguise.
Mayhem {2}{U} (You may cast this card from your graveyard for {2}{U} if you discarded it this turn. Timing rules still apply.)

Yavimaya, Cradle of Growth

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

Stormchaser Mage

Flying, haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)