ce medium human humanoid 

Perception +16

Languages Abyssal, Common, Tratrith

Skills Athletics +12, Demon Lore +13, Diplomacy +13 (+15 against demons), Intimidation +15, Religion +16, Survival +12

Str +2 Dex +1 Con +1 Int +1 Wis +4 Cha +3

Items gluttonous spear, hide armor, key to Cursebreaker's lock, religious symbol of Saivaefind

AC  23; Fort +13, Ref +11, Will +16

HP 90

Protect the Master [R] (auditory, emotion, linguistic, move) Trigger Thiagaistoth is targeted with an attack and a lower-ranking cultist is adjacent to him; Effect Thiagaistoth orders their cultist to leap in front of the attack. The cultist and Thiagaistoth swap places, and the cultist becomes the target of the attack.

Speed 25 feet

Melee [>] spear +17 (fatal d10, magical), Damage 3d6+4 piercing

Ranged [>] spear +16 (fatal d10, magical, thrown 20 feet), Damage 3d6+4 piercing

Divine Prepared Spells DC 24, attack +16; 3rd chilling darkness, fear, harm; 2nd death knell, heal, see invisibility, spiritual weapon; 1st bane, bless, command, ray of enfeeblement; Cantrips (3rd) daze, forbidding ward, light, stabilize

Divine Focus Spells DC 24, 2 Focus Points; 3rd touch of obedience (with a range of 30 feet)

Divine Rituals DC 24; Abyssal pact

Demonic Strength Thiagaistoth inflicts an extra 1d6 damage with his spear, and any spear gains the fatal trait while Thiagaistoth is using it (both the extra weapon damage die and the fatal trait have already been included in Thiagaistoth's spear Strikes above).

Steady Spellcasting If a reaction would disrupt Thiagaistoth's spellcasting action, on a successful DC 15 flat check, the action isn't disrupted.

The Slithering, page 33.