Cavern of Souls

As this land 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.

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Mountain

Secluded Courtyard

As this land 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 or activate an ability of a creature source of the chosen type.

Molten Duplication

Create a token that's a copy of target artifact or creature you control, except it's an artifact in addition to its other types. It gains haste until end of turn. Sacrifice it at the beginning of the next end step.

Sunspine Lynx

Players can't gain life.
Damage can't be prevented.
When this creature enters, it deals damage to each player equal to the number of nonbasic lands that player controls.

Flamebraider

{T}: Add two mana in any combination of colors. Spend this mana only to cast Elemental spells or activate abilities of Elemental sources.

Deceit

When this creature enters, if {U}{U} was spent to cast it, return up to one other target nonland permanent to its owner's hand.
When this creature enters, if {B}{B} was spent to cast it, target opponent reveals their hand. You choose a nonland card from it. That player discards that card.
Evoke {U/B}{U/B}

Twinflame Travelers

Flying
If a triggered ability of another Elemental you control triggers, it triggers an additional time.

Riverpyre Verge

{T}: Add {R}.
{T}: Add {U}. Activate only if you control an Island or a Mountain.

Champion of the Path

As an additional cost to cast this spell, behold an Elemental and exile it. (Exile an Elemental you control or an Elemental card from your hand.)
Whenever another Elemental you control enters, it deals damage equal to its power to each opponent.
When this creature leaves the battlefield, return the exiled card to its owner's hand.

Island

Kindle the Inner Flame

Create a token that's a copy of target creature you control, except it has haste and "At the beginning of the end step, sacrifice this token."
Flashback—{1}{R}, Behold three Elementals. (You may cast this card from your graveyard for its flashback cost. Then exile it. To behold an Elemental, choose an Elemental you control or reveal an Elemental card from your hand.)

Eclipsed Flamekin

When this creature enters, look at the top four cards of your library. You may reveal an Elemental, Island, or Mountain card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Three Steps Ahead

Spree (Choose one or more additional costs.)
+ {1}{U} — Counter target spell.
+ {3} — Create a token that's a copy of target artifact or creature you control.
+ {2} — Draw two cards, then discard a card.

Vibrance

When this creature enters, if {R}{R} was spent to cast it, this creature deals 3 damage to any target.
When this creature enters, if {G}{G} was spent to cast it, search your library for a land card, reveal it, put it into your hand, then shuffle. You gain 2 life.
Evoke {R/G}{R/G}

Steam Vents

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

Ashling, Rimebound

Whenever this creature transforms into Ashling, Rimebound and at the beginning of your first main phase, add two mana of any one color. Spend this mana only to cast spells with mana value 4 or greater.
At the beginning of your first main phase, you may pay {R}. If you do, transform Ashling.

Ashling, Rekindled

Whenever this creature enters or transforms into Ashling, Rekindled, you may discard a card. If you do, draw a card.
At the beginning of your first main phase, you may pay {U}. If you do, transform Ashling.