Below Eyal, something is calling. Deep in the tunnels, past the dwarven fortress of Iron Gate, you have stumbled upon a Light...

This addon adds a new campaign set in the depths below the Iron Throne, during an unknown time period.

This adds three new classes, two of which are loosely based on the Headless Horror, plus a mini-adventurer that gets talents from all three.
All are considered Demented, but use a new resource instead of insanity and do *not* require Forbidden Cults.
Their talents do not appear on enemies.

Hekatonkhieres are spell-using melee combatants who mix armed and unarmed attacks while accompanied by their eldritch Wandering Eyes.

New Talents
Spell / Shambler: This tree defines your combat style: stomp up to your target and wind up to a single devastating blow.
Spell / Headless Horror: Extract your own eyes from your head and empower them into monstrous minions for both attack and defense.
Technique / Titanic Blows: Heavy attacks with your weapons, which gain space-warping powers later on.
Technique / Helping Hands: Use your other 98 hands to block, steal, distract, and heal.
Technique / Harming Hands: Use your other 98 hands to grab, crush, drag, and batter.

Advanced Talents
Spell / Mountainshaper: Locked but available at level 0, your eldritch presence spills out into the world and warps the ground.
Technique / Splintered Lord: Time your attacks to take advantage of your extra-dimensional nature - or just chop enemies in half
Spell / Eyesight: Improve and direct your Wandering Eyes to better protect you and afflict your enemies.

Old Talents:
Cunning / Survival
Technique / Conditioning

By special request:
Argosines are summoners who are heavily dependent on their Wandering Eyes to fight, but get more and better eyes than the Hekatonkhiere.

New Talents
Spell / Sybarite: You can never hide behind corners, but you can walk through walls.
Spell / Headless Horror
Spell / Watcher: Banish enemies, empower your eyes with elemental magic, and keep up a swarm of them.
Spell / Veiled Shepherd: Actively command your eyes with extra beams, whirls, and energy.
Spell / Hale Hands: Use your other 98 hands to block, steal, defend, and overcome.

Advanced Talents
Spell / Oubliette: Locked but available at level 0, your eldritch presence spills out into the world and brings endless woe.
Spell / Eyebite: Teach your eyes to taunt, slow, and petrify, or rip out an enemy's eyes to serve you.
Spell / Eyesight

Old Talents:
Cunning / Survival
Spell / Divination

Kharybdians are ocean mages who mix attack spells, summons, and a precise sense of timing.

New Talents
Spell / Bloodtide: Cast your spells at the right time for extra effects, and always take one turn per turn.
Spell / Oceansong: Add destructive and distracting music to your talents.
Spell / Intrusion: Conjure your alien anatomy into the real world to destroy your enemies with claw, eyeball, and tentacle.
Spell / Polyps: Summon carnivorous coral into enemies, then sacrifice it to protect yourself.
Spell / Chronorium: Teleport back and forth, and deal with today's damage tomorrow.

Advanced Talents
Spell / Marching Sea: Locked but available at level 0, channel the myths of the other place to disable your enemies and rain down blood.
Spell / Null Vizier: Control the light to hide, attack, and defend.
Spell / Moon Wurm: You've finally realized, you aren't just you, you're someone else too. The Moon Wurm provides random support and a powerful summon.

Generic Talents

Old Talents:
Cunning / Survival
Otherness
Other Page: Use your many many limbs to achieve mastery of magic and items.

There aren't enough subtypes of dwarf so here are some Horrible dwarves.

An edit of the Worm's Don't Walk Addon, prevents Worms That Walk, Nightmare Horrors, and Dreaming Horrors from being spawned.