Sinspawn are presumably fiends that are formed by outlets of the multitude of pyreflies that composes Sin’s physical form. Collectively, the forms of Sinspawn coincide with those of reef-dwelling creatures, such as anemones and jellyfish. – DMLeibfrid
Geneaux – Sinspawn (CR 8)
NE Huge Aberration
Init +5; Senses Blindsight 60 ft.; Perception +12
AC 18, touch 6, flat-footed 18 (-2 size, -2 Dex, +12 natural)
hp 142  (15d8+75)
Fort +9, Ref +3, Will +11
Absorb Water; Defensive Ability Full Defense; Immune Antagonized, Blind, Doom, Gravity, Petrify, Poison, Sleep, Zombie
Speed Swim 40 ft., Fly 20 ft.
Melee 2 Tentacles +16 (2d6+6 plus poison)
Space 15 ft.; Reach 15 ft.
Special Attacks Sigh, Staccato
Spells Known (SC CL 10th, Concentration +12)
1st (DC 13) – Water
2nd (DC 14) – Water II
3rd (DC 15) – Water III
Str 22, Dex 7, Con 19, Int 4, Wis 14, Cha 12
Base Atk +11; CMB +19; CMD 27
Feats Blind Fight, Cleave, Extra MP, Improved Natural Armor, Power Attack, Toughness, Vital Attack, Weapon Focus (Tentacle)
Skills Fly +4, Perception +12, Stealth +12
Full Defense (Ex)
As a standard action, the Geneaux begins to rapidly recover, increasing its natural armor bonus by +10 and gaining fast healing 10 for 1d4+1 rounds.
Bite – injury; save Fort DC 21; frequency 1/round for 4 rounds; effect 1d12 non-elemental damage; cure 1 save.
Once every 1d4 rounds as a standard action, the Geneaux releases a long sigh that inflicts 10d4 points of wind damage to all opponents within 30 ft. radius around it and those within the radius must make a Reflex save (DC 19) for half damage. The Geneaux can Sign during Full Defense.
Once every 1d4 rounds as a standard action, the Geneaux drops down a barrage of whip like attacks that inflict 10d4 points of water and Bludgeoning damage to all opponents within a 15 foot cone and those within range must make a Reflex save (DC 19) for half damage.