Mountain

Conclave Equenaut

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Flying

Stonecoil Serpent

Reach, trample, protection from multicolored
Stonecoil Serpent enters with X +1/+1 counters on it.

Tectonic Hazard

Tectonic Hazard deals 1 damage to each opponent and each creature they control.

Paladin Class

(Gain the next level as a sorcery to add its ability.)
Spells your opponents cast during your turn cost {1} more to cast.
{2}{W}: Level 2
Creatures you control get +1/+1.
{4}{W}: Level 3
Whenever you attack, until end of turn, target attacking creature gets +1/+1 for each other attacking creature and gains double strike.

Leyline Binding

Flash
Domain — This spell costs {1} less to cast for each basic land type among lands you control.
When Leyline Binding enters, exile target nonland permanent an opponent controls until Leyline Binding leaves the battlefield.

Pyroceratops

Trample
Whenever you cast a noncreature spell, put a +1/+1 counter on Pyroceratops.

God-Pharaoh's Faithful

Whenever you cast a blue, black, or red spell, you gain 1 life.

Odric, Lunarch Marshal

At the beginning of each combat, creatures you control gain first strike until end of turn if a creature you control has first strike. The same is true for flying, deathtouch, double strike, haste, hexproof, indestructible, lifelink, menace, reach, skulk, trample, and vigilance.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Kill Shot

Bladetusk Boar

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Zetalpa, Primal Dawn

Flying, double strike, vigilance, trample, indestructible

Baird, Argivian Recruiter

At the beginning of your end step, if you control a creature with power greater than its base power, create a 1/1 white Soldier creature token.

Skyknight Legionnaire

Thundering Raiju

Haste
Whenever Thundering Raiju attacks, put a +1/+1 counter on target creature you control. Then Thundering Raiju deals X damage to each opponent, where X is the number of modified creatures you control other than Thundering Raiju. (Equipment, Auras you control, and counters are modifications.)

Furycalm Snarl

As Furycalm Snarl enters, you may reveal a Mountain or Plains card from your hand. If you don't, Furycalm Snarl enters tapped.
{T}: Add {R} or {W}.

Luminarch Aspirant

At the beginning of combat on your turn, put a +1/+1 counter on target creature you control.

Plains

Etali, Primal Storm

Whenever Etali attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.

Rohirrim Lancer

Menace (This creature can't be blocked except by two or more creatures.)
When Rohirrim Lancer dies, the Ring tempts you.

Keldon Flamesage

Enlist
Whenever Keldon Flamesage attacks, look at the top X cards of your library, where X is Keldon Flamesage's power. You may exile an instant or sorcery card with mana value X or less from among them. Put the rest on the bottom of your library in a random order. You may cast the exiled card without paying its mana cost.

Mounted Dreadknight

Trample
Mounted Dreadknight enters with a +1/+1 counter on it if an opponent lost life this turn.

Soldier of the Grey Host

Flash
Flying
When Soldier of the Grey Host enters, target creature gets +2/+0 until end of turn.

Electrostatic Infantry

Trample
Whenever you cast an instant or sorcery spell, put a +1/+1 counter on Electrostatic Infantry.