Running a 5e conversion of the 2nd edition adventure “A Darkness Gathering” – a campaign I have just called Thoughts of Darkness (heavily inspired by Bloodborne).  Its tuned to level 14 characters and my party is made up of 6 to 8 PCs.  Though in this encounter there were “only” six. The phthisic lairs in the sewers of the city of Yharnam (Stormport in the original).  The characters followed the monster’s tracks into the sewer system and discovered its lair – The Testament of the Mind.


Large aberration, chaotic evil
Armor Class 18 (natural armor)
Hit Points 280 (20d10 + 80)
Speed 40 ft.

20 (+5) 15 (+2) 19 (+4) 15 (+2) 10 (+0) 16 (+3)

Saving Throws CON +9
Skills Arcana +6, Perception +8, Stealth +12
Damage Resistances Cold; bludgeoning, piercing and slashing from nonmagical attacks.
Senses Blindsight 60 ft., Darkvision 60 ft., Passive Perception 18
Languages Common, Telepathy 60 ft.
Challenge 14 (11,500 XP)

Chill Aura. All creatures that start their turn within 10 feet of the phthisic suffer 3 (1d6) points of cold damage. The phthisic may turn this trait on and off as a bonus action. However, even when it is not active the area around a phthisic is unusually cold.

Chaotic Magic Resistance. The phthisic has advantage on saving throws against spells and other magical effects. If it saves against a magical attack the spell is reflected back at the caster.

Regeneration. The phthisic regains 10 hit points at the start of its turn so long as its anchor is not destroyed, and it has not taken any psychic damage.

Stalk the Senseless. The phthisic is invisible to feebleminded or stunned creatures.

Multiattack. The phthisic makes three attacks: one with its bite and two with its claws.

Frenzied Multiattack (only if the Anchor has been damaged).The phthisic makes four attacks: one with its bite and three with its claws. The number of attacks increase by 1 additional claw or bite attack each time the Anchor takes 100 additional points of damage (or part thereof). The fury that causes this frenzy fades after 1 minute.

Bite. Melee Weapon Attack:+9 to hit, reach 5 ft., one target.
Hit: 14 (2d8 + 5) piercing damage plus 14 (4d6) psychic damage. The target is also subjected to a feeblemind spell that lasts for 1 minute on a failed DC 15 Intelligence saving throw.

Claws.Melee Weapon Attack:+9 to hit, reach 5 ft., one target.
Hit: 16 (2d10 + 5) slashing damage plus 7 (2d6) psychic damage.

Anchor Return (1/Day).The phthisic gains one final benefit from its generative source: No matter the distance, the creature can see the interior of its lair and teleport without error back there at the first sign of intrusion.

Appearing as a savage and monstrous humanoid, the phthisic has one arm much larger than the other and uses it to walk with. It almost has a human face.

Use these options to make the phthistic more deadly.  These should definitely be used when the group is larger than 4 PCs.  I used all of these.

Celerity. The phthisic gains four initiative counts while in its lair. These may be rolled randomly or use the following order 30, 20, 15 and 10.

Legendary Stamina.  The phthisic may make a server through to end an ongoing effect at each initiative count he has. Also, effects that end after a round end after the next inaitive count.

Shared Hit Points. While within its lair, the phthisic splits all damage between itself and the anchor. The anchor can apply its damage threhold to these attacks. The anchor pulses whenever it takes damage in this way.


Screen Shot 2018-10-27 at 14.13.59.jpg
The Phthisic

The phthistic’s lair is where its Anchor is:

Every inch of the walls and ceilings are covered in etchings of maddened fiendish faces, their mouths a dark and hollow.  An obsidian column glowing with arcane writings dominates the room.  These runes give off a sickly green glow and hurt your head to look upon them. Curling mist covers the floor.

Perception 23: Something writhes in the mist, like a tendril or serpentine creature.

Characters need to make a DC 15 Sanity Saving Throw the first time they see it.  The anchor has 280 hit points and a damage threshold of 10. It is immune to psychic damage and resistant to all other nonmagical attacks. Every time the anchor takes damage the phthisic winces in pain. 

In addition to having the phthisic itself as a defence mechanism (see the teleport option of the phthisic) the Anchor can generate the following hazard/trap to defend the lair (or the phthisic if it is in the same area):

Grasping Mist
Wisps emerge from the mist, solidifying and lashing at you.

Perception 23: Character spots the grasping mist before it attacks and is not surprised.
Arcana 18: Characters understand that the Anchor is the focus of the trap.
Arcana 23: The character’s knowledge provides a +2 bonus to Dexterity (Thieves Tool) attempts to disable the trap.  Requires the Help action if the rogue didn’t make the arcane check.

While active all creatures in the room that start their turn in the area of the mist, except the phthisic, must make a DC 16 Wisdom saving throw or take 14 (2d10 +3) necrotic damage and the target is pushed back from the Anchor 10 feet and has disadvantage on saving throws, ability and skill checks for 1 minute.  On a success, the target takes only half damage and is not pushed back.

The anchor can also make a free attack against any creature that damaged it within the mist at the end of the attacker’s turn.

Counter Measures
Arcana/Thieves Tools DC 26. Disables the trap.
Arcana DC 20. Clears a 5-foot cube of mist until the end of the grasping mist’s next turn preventing the mist from attacking anyone standing in the cleared area.
Attack Action. Prepare an action to attack a tentacle that tries to grasp the character. On a to-hit roll of 26, the tentacle is beaten back and the character is not attacked.