Soul-Scar Mage

Prowess
If a source you control would deal noncombat damage to a creature an opponent controls, put that many -1/-1 counters on that creature instead.

Reckless Impulse

Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

Seek the Beast

Exile the top two cards of your library. Until your next end step, you may play those cards.

Questing Druid

Whenever you cast a spell that's white, blue, black, or red, put a +1/+1 counter on Questing Druid.

Questing Druid // Seek the Beast

Mana Confluence

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

Runaway Steam-Kin

Whenever you cast a red spell, if Runaway Steam-Kin has fewer than three +1/+1 counters on it, put a +1/+1 counter on Runaway Steam-Kin.
Remove three +1/+1 counters from Runaway Steam-Kin: Add {R}{R}{R}.

Stomping Ground

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

Copperline Gorge

Copperline Gorge enters tapped unless you control two or fewer other lands.
{T}: Add {R} or {G}.

Mountain

Showdown of the Skalds

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Exile the top four cards of your library. Until the end of your next turn, you may play those cards.
II, III — Whenever you cast a spell this turn, put a +1/+1 counter on target creature you control.

Inspiring Vantage

Inspiring Vantage enters tapped unless you control two or fewer other lands.
{T}: Add {R} or {W}.

Chained to the Rocks

Enchant Mountain you control
When Chained to the Rocks enters, exile target creature an opponent controls until Chained to the Rocks leaves the battlefield. (That creature returns under its owner's control.)

Sacred Foundry

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

Crash Through

Creatures you control gain trample until end of turn. (Each of those creature can deal excess combat damage to the player or planeswalker it's attacking.)
Draw a card.

Pia Nalaar, Consul of Revival

Thopters you control have haste.
Whenever you play a land from exile or cast a spell from exile, create a 1/1 colorless Thopter artifact creature token with flying.

Monastery Swiftspear

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