Arlinn, the Moon's Fury

Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)
+2: Add {R}{G}.
0: Until end of turn, Arlinn, the Moon's Fury becomes a 5/5 Werewolf creature with trample, indestructible, and haste.

Arlinn, the Pack's Hope

Daybound (If a player casts no spells during their own turn, it becomes night next turn.)
+1: Until your next turn, you may cast creature spells as though they had flash, and each creature you control enters with an additional +1/+1 counter on it.
−3: Create two 2/2 green Wolf creature tokens.

Arlinn, the Pack's Hope // Arlinn, the Moon's Fury

Tovolar, the Midnight Scourge

Whenever a Wolf or Werewolf you control deals combat damage to a player, draw a card.
{X}{R}{G}: Target Wolf or Werewolf you control gets +X/+0 and gains trample until end of turn.
Nightbound

Tovolar, Dire Overlord

Whenever a Wolf or Werewolf you control deals combat damage to a player, draw a card.
At the beginning of your upkeep, if you control three or more Wolves and/or Werewolves, it becomes night. Then transform any number of Human Werewolves you control.
Daybound

Tovolar, Dire Overlord // Tovolar, the Midnight Scourge

Faceless Haven

{T}: Add {C}.
{S}{S}{S}: Faceless Haven becomes a 4/3 creature with vigilance and all creature types until end of turn. It's still a land. ({S} can be paid with one mana from a snow source.)

Lord of the Ulvenwald

Other Wolves and Werewolves you control get +1/+1.
Whenever Lord of the Ulvenwald attacks, add {R} or {G}. Until end of turn, you don't lose this mana as steps and phases end.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Kessig Naturalist

Whenever Kessig Naturalist attacks, add {R} or {G}. Until end of turn, you don't lose this mana as steps and phases end.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Kessig Naturalist // Lord of the Ulvenwald

Werewolf Pack Leader

Pack tactics — Whenever Werewolf Pack Leader attacks, if you attacked with creatures with total power 6 or greater this combat, draw a card.
{3}{G}: Until end of turn, Werewolf Pack Leader has base power and toughness 5/3, gains trample, and isn't a Human.

Snow-Covered Mountain

Snow-Covered Forest

Fabled Passage

{T}, Sacrifice Fabled Passage: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Wolf

Frost Bite

Frost Bite deals 2 damage to target creature or planeswalker. If you control three or more snow permanents, it deals 3 damage instead.

Storm-Charged Slasher

At the beginning of combat on your turn, target creature you control gets +2/+0 and gains trample and haste until end of turn.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Reckless Stormseeker

At the beginning of combat on your turn, target creature you control gets +1/+0 and gains haste until end of turn.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Reckless Stormseeker // Storm-Charged Slasher

Ascendant Packleader

Ascendant Packleader enters with a +1/+1 counter on it if you control a permanent with mana value 4 or greater.
Whenever you cast a spell with mana value 4 or greater, put a +1/+1 counter on Ascendant Packleader.

Ranger Class

(Gain the next level as a sorcery to add its ability.)
When Ranger Class enters, create a 2/2 green Wolf creature token.
{1}{G}: Level 2
Whenever you attack, put a +1/+1 counter on target attacking creature.
{3}{G}: Level 3
You may look at the top card of your library any time.
You may cast creature spells from the top of your library.

Highland Forest

({T}: Add {R} or {G}.)
Highland Forest enters tapped.

Blizzard Brawl

Choose target creature you control and target creature you don't control. If you control three or more snow permanents, the creature you control gets +1/+0 and gains indestructible until end of turn. Then those creatures fight each other. (Each deals damage equal to its power to the other.)