Baernaloth (Variant)

   On the surface level, a Baernaloth is to the Yugoloths what a Pit Fiend is to Devils, or a Balor is to Demons. The mightiest and most vile of their species, who hold absolute authority over their kind and answer only to unique archfiends. While this is technically accurate, this description only scratches the surface of the terrifying, existential, absolute horror that Baernaloths represent.

   Baernaloths are the oldest Fiends in existence, predating the creation of the Abyss entirely, as well as the coming of Bateezu to hell. They also aren't technically Yugoloths, as they are the creators of that mercenary race of pure evil. Yugoloths treat Baernaloths with great respect and fear, but the elder fiends keep to themselves, rarely interacting with their creations, except to hand down tasks or orders. These are always obeyed without question, for every Yugoloth knows that to defy a Baernaloth is simply a slow, horrific suicide.

    Baernaloths can be found in the Grey Wastes of Hades, never on Gehenna. They crawled from the muck and ash of the plane at the beginning of time, and refused to migrate with their children to the neighboring plane. A Baernaloth is the purest expression of evil in all the Great Wheel, and they forged the Yugoloths in imitation of that. They are pure sociopaths, incapable of kindness, empathy, or most other emotions common among sentient life. They inflict pain and suffering out of boredom, as much as any grand plans of domination of conquest. But don't mistake their lack of feelings for an ignorance of morality. These beings are not animals, acting on instinct, or creatures so alien as to misunderstand good and evil. They are hyper-intelligent, have spent millenia pondering the beliefs and thoughts of mortal & fiendish races, understand their philosophies as well as the greatest sages, and knowingly choose to spread evil at every opportunity, rejecting Good, Law, and Chaos with equal disgust.

   Physically, a Baernaloth is a 9-foot tall, emaciated creature, with diseased, patchy fur, skin stretched too tight over its bones, massive antlers jutting from its skull, and yellowing fangs protruding from its jaws. In essence, they resemble the stereotypical Horned Fiend of old. While they're stronger then they look, and their claws and fangs can inflict terrible wounds, a Baernaloth's power isn't expressed well in a brawl. Even their formidable spellcasting is secondary to the webs of deception, and cruel plots they weave. It's a rare thing Indeed for a Baernaloth to step out from behind the curtain, set down its puppet strings and personally indulge in violence, but when they do, the targets of their malice find the experience akin to facing an evil demigod.

CR Note: The Potential healing from Power Word Heal isn't factored into the Baernaloth's CR, as counterspell is a thing, and its unlikely to be able to cast the spell right when it's at 10 hit points or so regardless. Accounting for the chance to recover its entire hit point pool, the Baernaloth would be CR 28, and as fierce as these entities are, that's not an accurate representation of its power, as a monster with no Legendary Resistance or legendary actions, even if the spell lets it stay alive for an extra couple rounds. On the other hand, no two Baernaloths are alike, and these variants listed below may provide an extra bit of challenge, and make them feel more like the Ancient Evil's they are.

Root of Evil: By meditating for 1 week, and performing vile experiments on itself, a Baernaloth can Mimic the ability of any Fiend. This manifests physically, and can be a Balor's Fire Aura, a Marilith's Reactive Trait, or a Horned Devil's Wings for flight. It can only have one of these trails at a time.

Summon Child: As the original Fiends, once a day as an action, a Baernaloth can summon any Fiend of the Great Wheel to its aid, the only exceptions being Oberyths, from beyond the Great Wheel (No Sibriex, Alkiliths, or Pazuzu, Etc.) It can even summon unique Archfiends, though such beings (any being over CR 20) will not be under its control, and may even be hostile to it when it arrives. Fiends that are CR 20 or lower, and summoned in this way obey its command and aid it in battle. They appear in an unoccupied space within 50 feet, remain for 10 minutes, and disappear if the Baernaloth is Slain (Those above CR 20 do not disappear with the death of the Baernaloth). A Baernaloth is Loathe to use this ability, as lesser fiends disgust it, and it considers all other fiends "Lesser."

Withering: A creature that fails their saving throw against a Baernaloth's Wounding trait, after being hit with one of its physical attacks, also gains a level of exhaustion. A creature can have no more then 3 levels of Exhaustion inflicted on it in this way.

Profane Regeneration: A Baernaloth Regenerates 10 hit points at the start of its turn. If a Baernaloth takes radiant damage, this trait doesn't function at the start of its next turn. A Baernaloth dies only if it starts its turn with 0 hit points and doesn't regenerate (note the synergy with Shield of the Innocent). Additionally, unless its body is removed from Hades and Buried on Consecrated Ground, it returns to life in 6d6+6 days with full hit points.

Life Drain: The Baernaloth regains hit points equal to half the necrotic damage dealt by its Wounding trait.

As I Die: When a creature deals a Killing Blow to a Baernaloth, they must make a DC 20 wisdom saving throw. On a failure, the spirit of the Baernaloth enters them, and begins devouring their soul, slowly turning them into a Baernaloth. A creature afflicted by this ability cannot benefit from a Long Rest, and upon gaining 6 levels of Exhaustion is transformed into a Baernaloth, with the memories, personality and abilities of the one they killed. A Wish spell can slow down the process once the Baernaloth's spirit enters its killer, temporarily suppressing the effect, but after failing the initial save no magic can stop the transformation. The only way to save the victim is to allow the Baernaloth to take over, kill it again, and then cast True Resurrection on the body, which will revert to the original creature upon the Baernaloths death. Of course, this forces the new killer to make the saving throw, or the process begins anew...