Cthonic Vanguard

Some warriors do not conquer the Underdark — they acclimate to it.
The stone remembers them. The fungus leans toward them. The things with too many eyes do not see them as prey.

Level 3: Deep Acclimation

Your body and instincts have been permanently altered.

You gain:

• Darkvision (or +30 ft if you already have it)

• Advantage on saves vs poison and disease

• You count as one size larger when determining carrying capacity, shoves, and grapples

Additionally, choose one Underdark Adaptation:

Underdark Adaptations (Level 3)

Chitinous Growth
Once per turn when hit, reduce the damage by your Constitution modifier (minimum 1).

Fungal Symbiote
At the start of your turn, if you are below half HP, regain HP equal to your proficiency bonus (no action).

Predator’s Eyes
Creatures cannot gain advantage against you from being unseen.

Chitinous Growth

Once per turn when hit, reduce the damage by your Constitution modifier (minimum 1).

Fungal Symbiote

Once per turn when hit, reduce the damage by your Constitution modifier (minimum 1).

Predator’s Eyes

Creatures cannot gain advantage against you from being unseen.

Level 7: Aberrant Presence

Your presence unsettles creatures not born below.

• When a creature enters melee range of you for the first time on a turn, it must make a Wisdom save or have disadvantage on its next attack before the end of its turn.

• Aberrations and Underdark-native creatures instead have disadvantage on the save.

Additionally, you learn Deep Speech.

Level 10: Fauna Mimicry

You have learned to imitate the deadliest behaviors of Underdark predators.

Choose one when you finish a long rest:

Spider-Limbed Assault
You can climb difficult surfaces, including ceilings, and your reach increases by 5 ft during your turn.

Basilisk Stare (Suppressed)
Once per turn when you hit a creature, reduce its speed to 0 until the start of your next turn.

Carrion Instinct
You have advantage on attacks against creatures below half HP.

 

Level 15: Inherent Malevolence

The Underdark’s cruelty has etched itself into you.

When you reduce a creature to 0 HP:

• Choose one creature you can see within 30 ft

• That creature must make a Wisdom save or be frightened of you until the end of its next turn

If the creature is not native to the Underdark, it has disadvantage on the save.

Level 18: Apex Organism

You are no longer merely adapted — you are recognized.

• You are immune to poison damage and the poisoned condition

• You cannot be charmed or frightened by creatures that are not aberrations or fiends

• Aberrations must succeed on a Wisdom save to willingly move closer to you

Once per long rest, when you would be reduced to 0 HP, you instead drop to 1 HP and immediately make one weapon attack.