Karlach, Fury of Avernus

Whenever you attack, if it's the first combat phase of the turn, untap all attacking creatures. They gain first strike until end of turn. After this phase, there is an additional combat phase.
Choose a Background (You can have a Background as a second commander.)

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Beastmaster Ascension

Whenever a creature you control attacks, you may put a quest counter on Beastmaster Ascension.
As long as Beastmaster Ascension has seven or more quest counters on it, creatures you control get +5/+5.

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.

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Return of the Wildspeaker

Choose one —
• Draw cards equal to the greatest power among non-Human creatures you control.
• Non-Human creatures you control get +3/+3 until end of turn.

Moonlight Hunt

Choose target creature you don't control. Each creature you control that's a Wolf or a Werewolf deals damage equal to its power to that creature.

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.

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

Frenzied Trapbreaker

{1}, Sacrifice Frenzied Trapbreaker: Destroy target artifact or enchantment.
Whenever Frenzied Trapbreaker attacks, destroy target artifact or enchantment defending player controls.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Outland Liberator

{1}, Sacrifice Outland Liberator: Destroy target artifact or enchantment.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Outland Liberator // Frenzied Trapbreaker

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

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.

Howling Moon

At the beginning of combat on your turn, target Wolf or Werewolf you control gets +2/+2 until end of turn.
Whenever an opponent casts their second spell each turn, create a 2/2 green Wolf creature token.

Moonmist

Transform all Humans. Prevent all combat damage that would be dealt this turn by creatures other than Werewolves and Wolves. (Only double-faced cards can be transformed.)

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.

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

Nature's Claim

Destroy target artifact or enchantment. Its controller gains 4 life.

Rhythm of the Wild

Creature spells you control can't be countered.
Nontoken creatures you control have riot. (They enter with your choice of a +1/+1 counter or haste.)