Breaching Dragonstorm

When this enchantment enters, exile cards from the top of your library until you exile a nonland card. You may cast it without paying its mana cost if that spell's mana value is 8 or less. If you don't, put that card into your hand.
When a Dragon you control enters, return this enchantment to its owner's hand.

Charring Bite

Charring Bite deals 5 damage to target creature without flying. (Then shuffle this card into its owner's library.)

Twinmaw Stormbrood

Flying
When this creature enters, you gain 5 life.

Twinmaw Stormbrood // Charring Bite

Nurturing Bristleback

When this creature enters, create a 3/3 green Dinosaur creature token.
Forestcycling {2} ({2}, Discard this card: Search your library for a Forest card, reveal it, put it into your hand, then shuffle.)

Mountain

Altanak, the Thrice-Called

Trample
Whenever Altanak becomes the target of a spell or ability an opponent controls, draw a card.
{1}{G}, Discard this card: Return target land card from your graveyard to the battlefield tapped.

Coliseum Behemoth

Trample
When this creature enters, choose one —
• Destroy target artifact or enchantment.
• Draw a card.

Terramorphic Expanse

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Overlord of the Boilerbilges

Impending 4—{2}{R}{R} (If you cast this spell for its impending cost, it enters with four time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.)
Whenever this permanent enters or attacks, it deals 4 damage to any target.

Summon: Fenrir

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Crescent Fang — Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
II — Heavenward Howl — When you next cast a creature spell this turn, that creature enters with an additional +1/+1 counter on it.
III — Ecliptic Growl — Draw a card if you control the creature with the greatest power or tied for the greatest power.

Random Encounter

Shuffle your library, then mill four cards. Put each creature card milled this way onto the battlefield. They gain haste. At the beginning of the next end step, return those creatures to their owner's hand.
Flashback {6}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Forest

Pelakka Wurm

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
When this creature enters, you gain 7 life.
When this creature dies, draw a card.

Plains

Diamond Weapon

This spell costs {1} less to cast for each permanent card in your graveyard.
Reach
Immune — Prevent all combat damage that would be dealt to Diamond Weapon.

Springbloom Druid

When this creature enters, you may sacrifice a land. If you do, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.