Thunder of Unity

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — You draw two cards and you lose 2 life.
II, III — Whenever a creature you control enters this turn, each opponent loses 1 life and you gain 1 life.

Ureni, the Song Unending

Flying, protection from white and from black
When Ureni enters, it deals X damage divided as you choose among any number of target creatures and/or planeswalkers your opponents control, where X is the number of lands you control.

Goblin

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.

Yathan Roadwatcher

When this creature enters, if you cast it, mill four cards. When you do, return target creature card with mana value 3 or less from your graveyard to the battlefield.

Zurgo, Thunder's Decree

Warrior

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."

Dragonfire Blade

Equipped creature gets +2/+2 and has hexproof from monocolored.
Equip {4}. This ability costs {1} less to activate for each color of the creature it targets.

Mox Jasper

{T}: Add one mana of any color. Activate only if you control a Dragon.

Smile at Death

At the beginning of your upkeep, return up to two target creature cards with power 2 or less from your graveyard to the battlefield. Put a +1/+1 counter on each of those creatures.

Tarkir: Dragonstorm Promos