Calamity, Galloping Inferno

Haste
Whenever Calamity, Galloping Inferno attacks while saddled, choose a nonlegendary creature that saddled it this turn and create a tapped and attacking token that's a copy of it. Sacrifice that token at the beginning of the next end step. Repeat this process once.
Saddle 1

Congregation Gryff

Flying, lifelink
Whenever Congregation Gryff attacks while saddled, it gets +X/+X until end of turn, where X is the number of Mounts you control.
Saddle 3 (Tap any number of other creatures you control with total power 3 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Shepherd of the Clouds

Flying, vigilance
When Shepherd of the Clouds enters the battlefield, return target permanent card with mana value 3 or less from your graveyard to your hand. Return that card to the battlefield instead if you control a Mount.

Quilled Charger

Whenever Quilled Charger attacks while saddled, it gets +1/+2 and gains menace until end of turn. (It can't be blocked except by two or more creatures.)
Saddle 2 (Tap any number of other creatures you control with total power 2 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Seraphic Steed

First strike, lifelink
Whenever Seraphic Steed attacks while saddled, create a 3/3 white Angel creature token with flying.
Saddle 4 (Tap any number of other creatures you control with total power 4 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Steer Clear

Steer Clear deals 2 damage to target attacking or blocking creature. Steer Clear deals 4 damage to that creature instead if you controlled a Mount as you cast this spell.

Copperline Gorge

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

Lush Portico

({T}: Add {G} or {W}.)
Lush Portico enters the battlefield tapped.
When Lush Portico enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Plains

Outlaw Medic

Lifelink
When Outlaw Medic dies, draw a card.

Wylie Duke, Atiin Hero

Vigilance
Whenever Wylie Duke, Atiin Hero becomes tapped, you gain 1 life and draw a card.

Loran's Escape

Target artifact or creature gains hexproof and indestructible until end of turn. Scry 1.

Overgrown Farmland

Overgrown Farmland enters the battlefield tapped unless you control two or more other lands.
{T}: Add {G} or {W}.

Mountain

Sanguine Evangelist

Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)
When Sanguine Evangelist enters the battlefield or dies, create a 1/1 black Bat creature token with flying.