Wildsong Howler

Whenever this creature enters or transforms into Wildsong Howler, look at the top six cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Howlpack Piper

This spell can't be countered.
{1}{G}, {T}: You may put a creature card from your hand onto the battlefield. If it's a Wolf or Werewolf, untap Howlpack Piper. Activate only as a sorcery.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Howlpack Piper // Wildsong Howler

Hollowhenge Huntmaster

Hexproof
Other permanents you control have hexproof.
At the beginning of combat on your turn, put two +1/+1 counters on each creature you control.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Avabruck Caretaker

Hexproof
At the beginning of combat on your turn, put two +1/+1 counters on another target creature you control.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Avabruck Caretaker // Hollowhenge Huntmaster

Immerwolf

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Each other creature you control that's a Wolf or a Werewolf gets +1/+1.
Non-Human Werewolves you control can't transform.

Terror of Kruin Pass

Double strike
Werewolves you control have menace. (They can't be blocked except by two or more creatures.)
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Terror of Kruin Pass.

Kruin Outlaw

First strike
At the beginning of each upkeep, if no spells were cast last turn, transform Kruin Outlaw.

Kruin Outlaw // Terror of Kruin Pass

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

Wall of Blossoms

Defender
When Wall of Blossoms enters, draw a card.

Howlpack Resurgence

Flash (You may cast this spell any time you could cast an instant.)
Each creature you control that's a Wolf or a Werewolf gets +1/+1 and has trample.

Threats Undetected

Search your library for up to four creature cards with different powers and reveal them. An opponent chooses two of those cards. Shuffle the chosen cards into your library and put the rest into your hand.

The Celestus

If it's neither day nor night, it becomes day as The Celestus enters.
{T}: Add one mana of any color.
{3}, {T}: If it's night, it becomes day. Otherwise, it becomes night. Activate only as a sorcery.
Whenever day becomes night or night becomes day, you gain 1 life. You may draw a card. If you do, discard a card.

Howlpack Avenger

Whenever a permanent you control is dealt damage, Howlpack Avenger deals that much damage to any target.
{1}{R}: Howlpack Avenger gets +2/+0 until end of turn.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Ill-Tempered Loner

Whenever Ill-Tempered Loner is dealt damage, it deals that much damage to any target.
{1}{R}: Ill-Tempered Loner gets +2/+0 until end of turn.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Ill-Tempered Loner // Howlpack Avenger

Full Moon's Rise

Werewolf creatures you control get +1/+0 and have trample.
Sacrifice Full Moon's Rise: Regenerate all Werewolf creatures you control.