Azari, the Devourer's hero power is Devour. This is his deck. One more card should probably only have one copy - perhaps Demonwrath or Bane of Doom. I thought it was Doom!, but there are two of those.

King Togwaggle's hero power is Magic Candle which generates a random playable dungeon run treasure (no passive treasures such as Captured Flag). Like the other final bosses he starts his first turn on 3 mana. Here's his deck.

That is the intended function, just like Baron Rivendare and Weasel Tunneler, Malorne, and in some sense Sherazin, Corpse Flower. These deathrattles act on the cards themselves, not copies - there is no second card to return to your hand, or to deck, etc.

4

Azari, the Devourer's hero power is Devour. This is his deck. One more card should probably only have one copy - perhaps Demonwrath or Bane of Doom. I thought it was Doom!, but there are two of those.

1x Mal'Ganis

2x Abyssal Enforcer

2x Bane of Doom

2x Demonwrath

2x Despicable Dreadlord

2x DOOM!

2x Doomguard

2x Dread Infernal

2x Dreadsteed

2x Fearsome Doomguard

2x Flame Imp

2x Kabal Trafficker

2x Pit Lord

2x Voidcaller

2x Voidlord

2x Wrathguard

3

The Darkness's hero power is Encroaching Darkness. He begins his first turn with 3 mana. You start the fight with 3xLuminous Candles.

This is his deck.

1x Potion of Madness

2x Cabal Shadow Priest

2x Entomb

2x Evasion

2x Forbidden Shaping

2x Mind Control

2x Psychic Scream

2x Shadow Bolt

2x Shadow Word: Death

2x Shadow Word: Pain

2x Shadowfiend

2x Sudden Betrayal

2x Twisting Nether

3x Looming Presence

6

Vustrasz the Ancient's hero power is Vindictive Breath. Here's his deck.

1x Wrathion

1x Ysera

2x Azure Drake

2x Blackwing Corruptor

2x Chromatic Dragonkin

2x Cobalt Scalebane

2x Drakonid Operative

2x Hoarding Dragon

2x Holy Nova

2x Lightbomb

2x Looming Presence

2x Power Word: Tentacles

2x Spirit Lash

2x Twilight Whelp

2x Unidentified Elixir

2x Velen's Chosen

2

King Togwaggle's hero power is Magic Candle which generates a random playable dungeon run treasure (no passive treasures such as Captured Flag). Like the other final bosses he starts his first turn on 3 mana. Here's his deck.

2x Rakanishu (these may not be in his deck, but occasionally occurs)

2x Backstab

2x Beneath the Grounds

2x Evasion

2x Eviscerate

2x Evolved Kobold

2x Kobold Apprentice

2x Kobold Barbarian

2x Kobold Geomancer

2x Kobold Hermit

2x Kobold Illusionist

2x Kobold Monk

2x Sudden Betrayal

2x Tomb Pillager

2x Vanish

4

Bristlesnarl's hero power is Hunter's Call. Here's 28 cards in his deck. He wouldn't cast the other two even into fatigue.

1x Corpse Widow

1x Gahz'rilla

1x Giant Mastodon

1x Kathrena Winterwisp

1x King Krush

1x Swamp King Dred

2x Call of the Wild

2x Charged Devilsaur

2x Deadly Shot

2x Giant Sand Worm

2x Gladiator's Longbow

2x Kill Command

2x King of Beasts

2x King's Elekk

2x Savannah Highmane

2x Starving Buzzard

2x Tundra Rhino

6

Lava-Filled Chamber's hero power is The Floor is Lava. If it overkills a 1 health minion, Explosive Runes will deal 7 damage to your hero. Here's his deck.

1x Kalimos, Primal Lord

1x Ragnaros the Firelord

2x Explosive Runes

2x Fire Elemental

2x Fire Plume Phoenix

2x Fireball

2x Fireguard Destroyer

2x Firelands Portal

2x Flame Geyser

2x Flamestrike

2x Forbidden Flame

2x Lava Burst

2x Lava Shock

2x Pyroblast

2x Volcanic Potion

2x Volcano

5

Gutmook's hero power is Metabolized Magic. This is his deck.

1x King Mukla

1x Millhouse Manastorm

1x Troggzor the Earthinator

1x Volcano

2x Ancestral Knowledge

2x Burgly Bully

2x Burly Rockjaw Trogg

2x Crushing Hand

2x Flamewreathed Faceless

2x Gluttonous Trogg

2x Hoarding Dragon

2x Lava Shock

2x Lightning Storm

2x Snowfury Giant

2x Stormforged Axe

2x Totem Golem

2x Tunnel Trogg

79

Xol the Unscathed's hero power is Beam Me Up!, which generates one of these cards depending on her emote.

Fatality- Beam of DeathFatigue- Beam of DecayFear- Beam of FearFlame- Beam of FireFlummox- Beam of ConfusionFrost- Beam of FrostShe starts her first turn at 3 mana like the other final bosses. Here is her deck.

1x Blood-Queen Lana'thel

1x Clutchmother Zavas

1x Deathwing

1x Lakkari Sacrifice

2x Cataclysm

2x Corrupting Mist

2x Dark Bargain

2x Darkshire Librarian

2x Despicable Dreadlord

2x Doomguard

2x Flame Imp

2x Lakkari Felhound

2x Malchezaar's Imp

2x Silverware Golem

2x Soulfire

4x Howlfiend

3

Generated by Ixlid's hero power Sprouting Spore.

4

That is the intended function, just like Baron Rivendare and Weasel Tunneler, Malorne, and in some sense Sherazin, Corpse Flower. These deathrattles act on the cards themselves, not copies - there is no second card to return to your hand, or to deck, etc.