Koma, World-Eater

This spell can't be countered.
Trample, ward {4}
Whenever Koma deals combat damage to a player, create four 3/3 blue Serpent creature tokens named Koma's Coil.

Glacierwood Siege

As this enchantment enters, choose Temur or Sultai.
• Temur — Whenever you cast an instant or sorcery spell, target player mills four cards.
• Sultai — You may play lands from your graveyard.

Roar of Endless Song

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Create a 5/5 green Elephant creature token.
III — Double the power and toughness of each creature you control until end of turn.

Eshki Dragonclaw

Vigilance, trample, ward {1}
At the beginning of combat on your turn, if you've cast both a creature spell and a noncreature spell this turn, draw a card and put two +1/+1 counters on Eshki Dragonclaw.

Flubs, the Fool

You may play an additional land on each of your turns.
Whenever you play a land or cast a spell, draw a card if you have no cards in hand. Otherwise, discard a card.

Songcrafter Mage

Flash
When this creature enters, target instant or sorcery card in your graveyard gains harmonize until end of turn. Its harmonize cost is equal to its mana cost. (You may cast that card from your graveyard for its harmonize cost. You may tap a creature you control to reduce that cost by {X}, where X is its power. Then exile the spell.)

Temur Battlecrier

During your turn, spells you cast cost {1} less to cast for each creature you control with power 4 or greater.

Dragonback Assault

When this enchantment enters, it deals 3 damage to each creature and each planeswalker.
Landfall — Whenever a land you control enters, create a 4/4 red Dragon creature token with flying.