The Irencrag

{T}: Add {C}.
Whenever a legendary creature you control enters, you may have The Irencrag become a legendary Equipment artifact named Everflame, Heroes' Legacy. If you do, it gains equip {3} and "Equipped creature gets +3/+3" and loses all other abilities.

Bone-Cairn Butcher

Mobilize 2 (Whenever this creature attacks, create two tapped and attacking 1/1 red Warrior creature tokens. Sacrifice them at the beginning of the next end step.)
Attacking tokens you control have deathtouch.

Desperate Measures

Target creature gets +1/-1 until end of turn. When it dies under your control this turn, draw two cards.

Plains

Bleachbone Verge

{T}: Add {B}.
{T}: Add {W}. Activate only if you control a Plains or a Swamp.

Sunbillow Verge

{T}: Add {W}.
{T}: Add {R}. Activate only if you control a Mountain or a Plains.

Godless Shrine

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

Windcrag Siege

As this enchantment enters, choose Mardu or Jeskai.
• Mardu — If a creature attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
• Jeskai — At the beginning of your upkeep, create a 1/1 red Goblin creature token. It gains lifelink and haste until end of turn.

Mountain

Underfoot Underdogs

When this creature enters, create a 1/1 red Goblin creature token.
{1}, {T}: Target creature you control with power 2 or less can't be blocked this turn.

Zookeeper Mechan

{T}: Add {R}.
{6}{R}: Target creature you control gets +4/+0 until end of turn. Activate only as a sorcery.

All-Out Assault

Creatures you control get +1/+1 and have deathtouch.
When this enchantment enters, if it's your main phase, there is an additional combat phase after this phase followed by an additional main phase. When you next attack this turn, untap each creature you control.

Stadium Headliner

Mobilize 1 (Whenever this creature attacks, create a tapped and attacking 1/1 red Warrior creature token. Sacrifice it at the beginning of the next end step.)
{1}{R}, Sacrifice this creature: It deals damage equal to the number of creatures you control to target creature.

Sacred Foundry

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

Reigning Victor

Mobilize 1 (Whenever this creature attacks, create a tapped and attacking 1/1 red Warrior creature token. Sacrifice it at the beginning of the next end step.)
When this creature enters, target creature gets +1/+0 and gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Mardu Siegebreaker

Deathtouch, haste
When this creature enters, exile up to one other target creature you control until this creature leaves the battlefield.
Whenever this creature attacks, for each opponent, create a tapped token that's a copy of the exiled card attacking that opponent. At the beginning of your next end step, sacrifice those tokens.

Dalkovan Encampment

This land enters tapped unless you control a Swamp or a Mountain.
{T}: Add {W}.
{2}{W}, {T}: Whenever you attack this turn, create two 1/1 red Warrior creature tokens that are tapped and attacking. Sacrifice them at the beginning of the next end step.

Get Lost

Destroy target creature, enchantment, or planeswalker. Its controller creates two Map tokens. (They're artifacts with "{1}, {T}, Sacrifice this token: Target creature you control explores. Activate only as a sorcery.")

Voice of Victory

Mobilize 2 (Whenever this creature attacks, create two tapped and attacking 1/1 red Warrior creature tokens. Sacrifice them at the beginning of the next end step.)
Your opponents can't cast spells during your turn.

Braska's Final Aeon

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Jecht Beam — Each opponent discards a card and you draw a card.
III — Ultimate Jecht Shot — Each opponent sacrifices two creatures of their choice.
Menace

Jecht, Reluctant Guardian

Menace
Whenever Jecht deals combat damage to a player, you may exile it, then return it to the battlefield transformed under its owner's control.

Jecht, Reluctant Guardian // Braska's Final Aeon

Swamp

Zurgo, Thunder's Decree

Mobilize 2 (Whenever this creature attacks, create two tapped and attacking 1/1 red Warrior creature tokens. Sacrifice them at the beginning of the next end step.)
During your end step, Warrior tokens you control have "This token can't be sacrificed."