Ashnod's Altar

Dauntless Escort

Sacrifice Dauntless Escort: Creatures you control gain indestructible until end of turn.

Duergar Hedge-Mage

When Duergar Hedge-Mage enters, if you control two or more Mountains, you may destroy target artifact.
When Duergar Hedge-Mage enters, if you control two or more Plains, you may destroy target enchantment.

Savage Ventmaw

Flying
Whenever Savage Ventmaw attacks, add {R}{R}{R}{G}{G}{G}. Until end of turn, you don't lose this mana as steps and phases end.

Draconic Disciple

{T}: Add one mana of any color.
{7}, {T}, Sacrifice Draconic Disciple: Create a 5/5 red Dragon creature token with flying.

Bloodbraid Elf

Haste
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Knotvine Mystic

Dragon Arch

{2}, {T}: You may put a multicolored creature card from your hand onto the battlefield.

Urza's Filter

Multicolored spells cost {2} less to cast.

Rienne, Angel of Rebirth

Flying
Other multicolored creatures you control get +1/+0.
Whenever another multicolored creature you control dies, return it to its owner's hand at the beginning of the next end step.

Tome of the Guildpact

Whenever you cast a multicolored spell, draw a card.
{T}: Add one mana of any color.

Brion Stoutarm

Lifelink
{R}, {T}, Sacrifice another creature: Brion Stoutarm deals damage equal to the sacrificed creature's power to target player or planeswalker.

Sneak Attack

{R}: You may put a creature card from your hand onto the battlefield. That creature gains haste. Sacrifice the creature at the beginning of the next end step.

Saffi Eriksdotter

Sacrifice Saffi Eriksdotter: When target creature is put into your graveyard this turn, return that card to the battlefield.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Renegade Rallier

Revolt — When Renegade Rallier enters, if a permanent you controlled left the battlefield this turn, return target permanent card with mana value 2 or less from your graveyard to the battlefield.

Wild Cantor

({R/G} can be paid with either {R} or {G}.)
Sacrifice Wild Cantor: Add one mana of any color.

Burning-Tree Emissary

When Burning-Tree Emissary enters, add {R}{G}.

Radha, Heir to Keld

Whenever Radha, Heir to Keld attacks, you may add {R}{R}.
{T}: Add {G}.

Steward of Valeron

Purphoros, Bronze-Blooded

Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Other creatures you control have haste.
{2}{R}: You may put a red creature card or an artifact creature card from your hand onto the battlefield. Sacrifice it at the beginning of the next end step.

Loxodon Hierarch

When Loxodon Hierarch enters, you gain 4 life.
{G}{W}, Sacrifice Loxodon Hierarch: Regenerate each creature you control.

Scuttlemutt

{T}: Add one mana of any color.
{T}: Target creature becomes the color or colors of your choice until end of turn.

Trostani's Summoner

When Trostani's Summoner enters, create a 2/2 white Knight creature token with vigilance, a 3/3 green Centaur creature token, and a 4/4 green Rhino creature token with trample.

Qasali Pridemage

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{1}, Sacrifice Qasali Pridemage: Destroy target artifact or enchantment.