This actually made me remember that I had some new entries for the Deo'iel Guide to Survival (and that the entry on simulacra hasn't been added to it yet). Here are a few new immortals:

[HIDER=Shaltai][B]Shaltai (Singular: shalto)[/B]
[I]Occurrence:[/I] Appears in Reniam only when called here by a summoner, but are known to be extraordinarily difficult to maintain control of for extended periods of time, especially if they are made or allowed to use their special abilities. Even as such they are a rare sight, however, since their relatively low prowess and usefulness compared to the cost of summoning them, as well as the difficulty of controlling them, makes them inferior subjects for summoners to rely on. In the Lower Plane, spiritualists and scholars have speculated that shaltai are the result of mortals that have been consumed by destructive mental illness and driven to madness. Those who commit evil without understanding their own deeds or are held responsible for actions of other personalities within themselves are thought to become shaltai.
[I]Appearance:[/I] The briefest and most common description reported of shaltai name their physical forms that of “four-legged spiders”, although more in-depth examinations of these demons have shown a number of discrepancies between these and actual spiders. While they do share some semblance in the shape of their body and limbs, including a bulky abdominal hind-body consistent with orb-weavers and downward-facing fangs similar to those of certain species of spider, that is where the similarities end. Shaltai have only two eyes with the appearance of black orbs, and are known to have a “crown” of horn-like protrusions surrounding the thorax, with a distribution of half curving toward the head and half toward the abdomen of the creature. The exoskeleton and horns of shaltai are both black with red streaks, with the horns specifically have red tips. Behind their fangs shaltai have jaws more consistent with those of carnivorous reptiles than of spiders, providing it a powerful bite and an abundance of sharp teeth. Their abdominal segment is covered in particularly tough carapace and has been observed to be capable of receiving impacts that could shatter rock and metal alike without cracking, making them virtually impenetrable. Lastly, shaltai appear to lack a spinneret but instead have something akin to an extendable ovipositor where the spinneret would have been, surrounded by numerous smaller, tougher extremities the sole purpose of which appears to be to protect the ovipositor.
The size of shaltai is incredibly inconsistent, with reported sizes ranging from shaltai barely any larger than grains of sand to specimens several dozen feet long and weighing over three thousand pounds. They appear incapable of speech in any language as they simply lack functional vocal organs, but are capable of hissing, clicking and, rarely, emitting a “nasty” grinding noise described as “the sound of bones slowly being crushed by stone”.
[I]Danger:[/I] Shaltai are often considered the least useful possible being to summon, and can mostly be considered to be of negligible danger while under the control of a summoner as their heavy bodies, relatively weak limbs and lack of magical ability make them easy to outrun and outmaneuver. However, one should be mindful that being caught by a sizable shalto is almost certain to result in certain death, as they are not only typically much stronger than average humanoids and have a bite that can easily tear off limbs, but can additionally inject venom through their fangs that is usually lethal, and even in fortunate cases where the victim survives results in necrosis surrounding the bite.
That is not to say that the presence of shaltai should be taken lightly, however, and rather than prioritizing the defeat of the summoner, every effort possible should be made to dispatch these demons before dealing with the one controlling them. The true danger of shaltai is their special abilties, all of which can be summarized as a way for them to approximate the ability of deity-level immortals to split themselves into multiple entities. A shalto can use its ovipositor to literally separate part of its own mass, mind and power into an additional shalto, weakening the body of the original but allowing it to exist in two places at once... and, worryingly, this process appears to be almost infinitely repeatable, allowing a single large, powerful shalto to split into thousands of weaker shaltai, each one with a mind of its own but sharing information and a common will with the collective, and all of which retain the venom of the original, albeit in smaller quantities. Allowing a shalto to split furthermore makes it incredibly difficult to defeat, since killing any individual shalto-incarnation will result in the dispersal typical for immortals, only for the dispersed energy to be reabsorbed by the remaining incarnations of the same shalto, allowing them to recombine and grow in strength and size. The only way to defeat a shalto besides having a summoner banish it is to kill every single one of its incarnations, leaving its soul nowhere to retreat to besides the Lower Plane.
It is fortunate that shaltai splitting into multiple incarnations also multiplies the effort required to control them or shaltai might have been a much more common sight in Reniam than they currently are, as a single shalto can potentially become immensely dangerous if allowed to split itself enough times.
[I]Conclusion:[/I] All demons are exceedingly dangerous and must be slain on sight, which is a sentiment that is even more critical and urgent with shaltai than with most others of their kind. Every possible effort should be made to avoid killing a shalto’s summoner or causing the summoner to lose control of a shalto and, regardless of whether one has obtained freedom or remains controlled, should be defeated as soon as possible. Killing a shalto is best done by targeting their head, though this obviously also puts one at considerable risk as this is also where shaltai’s offensive capabilities are the greatest. Alternatively one can attempt to somehow turn a shalto over, as not only are they fairly harmless if laid on their back, but the carapace on the underside of their abdomens is also much softer than that on the top and sides, allowing one to inflict mortal wounds without getting in range of their fangs. In an emergency where no immediate opportunity to kill a shalto presents itself, it is worth noting that a shalto cannot split itself if its ovipositor is destroyed and that the organ, aside from the leg-like limbs protecting it, is quite fragile. A destroyed ovipositor will regenerate in a matter of seconds, however, making targeting it nothing more than a means to delay the shaltai splitting.[/HIDER]

[HIDER=Angels of Penance][B]Angels of Penance:[/B]
[I]Occurrence:[/I] Rarely venture to Reniam for other reasons than having been summoned, or as a messenger of a god. Spiritualists and scholars have speculated that angels of penance are the result of mortals who committed evil in the name of good, hunting down those in violation of their ethical standards and subjected them to cruel and brutal punishment, yet still managed to grow their Seeds of Good more than that of Evil, either due to their own conviction or the sharing of this conviction across a sect or religion that approved of it.
[I]Appearance:[/I] Angels of penance assume the appearance of completely black, featureless doll-like entities, creatures that draw a somewhat humanoid contour but with unusually long legs, arms and fingers, with their only distinctive feature being a pair of glowing white, lidless eyes in their otherwise empty faces. They generally have narrow, emaciated-looking frames, and have been observed to be between 6’ 2” and 7’ 10” tall. The manner they move is known to be odd and “puppet-like”, their bodies often contorting in impossible ways or bending at angles that should have caused them to lose balance without doing so. They are completely mute and silent with even their footfalls seeming lighter and more muffled than they should be.
[I]Danger:[/I] Unpredictable at best and downright hostile at worst, angels of penance are dangerous no matter whether they are controlled by a summoner or if they have regained their freedom, as they appear to all harbor a deep-seated desire to harm and punish all mortals for their sins, no matter how small or perception-based those sins might be. They are also incredibly dangerous opponents due to their quick, agile and freakishly nerveless movements, and are known to be able to leap several dozen feet with ease, move swiftly on vertical surfaces and ceilings and to have very limited sense of self-preservation, sometimes even acting as though they revel in any injuries inflicted upon them. Their physical abilities notwithstanding, however, they also possess two primary supernatural powers that make them deserving of the fear they tend to inspire. The first ability is that to render themselves briefly incorporeal, at once turning their forms partially translucent and allowing them to pass through physical obstacles unhindered; the second is the ability for their hands to penetrate practically anything, piercing through metal, flesh and bone effortlessly and – inexplicably – soundlessly.
[I]Conclusion:[/I] Unlike most other angels there is usually little advantage in aiming to end the summoner of an angel of penance as the angel is not only likely to remain hostile once it regains its freedom, but furthermore also liable to start targeting anyone else nearby whom it perceives to be a sinner to be punished. Angels of penance should thus be dealt with using both extreme prejudice and caution, as they are fearsome opponents indeed. Every effort should be made to evade their hands as there appears to be no way to protect oneself from their deadly touch, while one at the same time needs to remember that physical obstacles are by no means a reliable way of keeping them at a distance. That said it appears that causing lethal damage to an angel of penance’s head, neck or torso will kill it the same as it will a mortal, making slaying them a relatively simple matter... presuming, of course, that one can manage to land a blow against them.[/HIDER]

[HIDER=Angels of Fear][B]Angels of Fear[/B]
[I]Occurrence:[/I] Rarely venture to Reniam for other reasons than having been summoned, or as a messenger of a god. Spiritualists and scholars have speculated that angels of fear are the result of mortals who lived their lives specifically out of fear that they might end up in the Lower Plane, decidedly committing good almost solely for selfish reasons and ultimately being willing to sacrifice anything for their own self-preservation.
[I]Appearance:[/I] Angels of fear are green-skinned grub-like beings with faintly snake-like heads, usually no more than one or one and a half foot long. Their skin is soft and slimy, their somewhat flat, only remotely serpentine heads have no teeth of any kind, and they appear to have no eyes. They are physically completely defenseless and lack any meaningful means of locomotion. They can, however, both hear and speak.
[I]Danger:[/I] No matter whether angels of fear are controlled or not, or even who is controlling them, they are equally dangerous to everyone that gets near them. While they are physically unimposing to say the least, not to mention blind and generally harmless, they are capable of periodic teleportation with an apparent range of about a thousand feet and are known to exude a horrendous stench. More worryingly and relevantly, however, is the innate effect they have on anyone who looks at them directly [I]or[/I] who makes the mistake of going within sixty-five feet or less of it: anyone who does either of these things is immediately and inevitably trapped within their own minds, their bodies paralyzed by the angel’s magic, and are made to face their worst fears in a psychic arena of the victim’s own making. This experience has been known to be harrowing to even the bravest souls, leaving none without deep psychological scars, driving many insane and sometimes even rendering the victim permanently catatonic or making them suicidal from the intense, merciless self-discovery they are made to experience. One remains trapped within the angel’s illusion until one successfully faces and overcomes all of one’s worst fears, at which point the angel sets one free. Once someone reattains their freedom the angel is completely defenseless against that person, making killing it a simple matter.
[I]Conclusion:[/I] More so than with any other angel it is best to aim to end angels of fear’s summoners while avoiding the angels themselves at all costs, as even those with immense mental fortitude will at the very least be rendered paralyzed by the angel’s magic and thus be vulnerable to attacks from other sources. There is no generally applicable strategy with angels of fear if one succumbs to their magic, no advice to offer and no easy way to escape; all one can do is to face the trials the angel sends against one, however nightmarish and insurmountable they might seem, and try to persevere. If one manages to break free from the spell, however, it is important to remember that others might still be prisoners of the angel’s spell and kill it as quickly as possible, as doing so will immediately free anyone else from their individual nightmares.[/HIDER]