Still under construction.
The following fiend is inspired by voidwalkers and voidlords from World of Warcraft.
UMBRAWLER CR 4
NE Medium outsider (elemental, evil, extraplanar, fel'fiend)
Init +1; Senses darkvision 180 ft., low-light vision, see in darkness, Perception +13
AC 19, touch 11, flat-footed 18 (+1 Dex, +8 natural)
hp 57 (5d10+15+15); regeneration 1d2–1 (any)
Fort +7, Ref +7, Will +7; +4 vs. disease and poison
DR 5/magic; SR 15; Immune ability drain (taken as ability damage),
death by massive damage, death effects, elemental traits, energy drain,
paralysis, petrification, phantasms, involuntary polymorph effects, sleep effects
Resist acid 5, cold 15, electricity 5, fire 5, negative energy damage 15,
psychic energy damage 15, sonic 5
Defensive Abilities cosmic defiance, reign of darkness,
shadow blend, shadow bulwark
Speed fly 40 ft. (perfect), swim 30 ft.
Melee 2 adaptive arms +9 (2d6+4)
Space 5 ft.; Reach 5 ft.
Special Attacks adaptive arms, cosmic strike
Str 18, Dex 13, Con 17, Int 13, Wis 12, Cha 17
Base Attk +5; CMB +10; CMD 24
Feats Iron Will, Lightning Reflexes, Seize the Opportunity
Racial Bonus Feats Combat Patrol, Combat Reflexes, Conceal Scent,
Diehard, Endurance, Improved Natural Attack [claw, slam],
Lurker in Darkness, Mobility, Pin Down, Stand Still
Skills Acrobatics +9, Bluff +7, Escape Artist +9, Fly +16,
Intimidate +7, Knowledge (planes) +5, Perception +13,
Sense Motive +13, Spellcraft +9, Stealth +13, Swim +16
Racial Modifiers +4 Perception, +4 Sense Motive
Languages Abyssal, Auran, Celestial, Infernal; telepathy 300 ft.
SQ compression, concealed alignment, cosmic tolerance, insulated,
malleable gravitation, no breath, powerful build,
greater shadow slip, trackless step
Adaptive Arms (Ex) As an anytime free action, an umbrawler in true form may alter any number of its hands to feature a claw or slam attack. Any such slam attack may include spikes to deal both bludgeoning and piercing damage.
Concealed Alignment (Ex) Fel'fiends radiate no alignment aura. This affects only alignment detection, not effects that cause harm or are otherwise based on alignment.
Cosmic Defiance (Ex) When and wherever it is advantageous for them, stunned or cowering fel'fiends are only considered dazed.
Cosmic Strike (Su) The natural weapons of fel'fiends, as well as any weapons they wield, are considered ghost touch seaborne weapons and overcome all forms of damage reduction based on magic, alignment or material.
Cosmic Tolerance (Su) Fel'fiends adapt to hostile environments as per adapt body (psionic power).
Insulated (Ex) Against umbrawlers in true form, damage dealt by diffuse blunt trauma via battering, buffeting, compression, constriction, crushing, falling, impact collisions, shockwaves or trampling is halved and rounded down.
Malleable Gravitation (Ex) Although legless, umbrawlers in true form manipulate gravity and need not make Fly or Swim checks to undertake complex maneuvers. They still require such checks to resist external influences against them, such as strong winds or currents. When so enabled, one also gains a +4 racial bonus to Stealth checks and may apply their Strength modifier instead of their Dexterity modifier to any Fly check they make.
Reign of Darkness (Ex) An umbrawler adds its Charisma bonus (if any) to hit points gained per Hit Die, to Fortitude saving throws, to CMD, and to the number of attacks of opportunity it can make each round. In addition, the enemies of an umbrawler treat its threatened area as difficult terrain.
Shadow Blend (Su) For each step of illumination below bright light where it would receive an attack, an umbrawler in true form gains a degree of concealment (10% miss chance per step, up to 40%) from blending with shadows, overlapping with any gained from a lack of light. An umbrawler can suspend or resume this ability as an anytime free action.
Shadow Bulwark (Su) Once per 10 minutes as a free or immediate action, an umbrawler may gain temporary hit points equal to its Hit Dice for each step of illumination below bright light through most its space. These temporary hit points last for 1 minute.
Shadow Slip, Greater (Su) For each step of illumination below bright light through most its space, an umbrawler gains a +4 racial bonus on Stealth checks.