Sehen magic (Sehenautosis) is a rare, specific, peculiar type of magic that has been revered for centuries in the Rimean faith. Those that poses this type of magic are called Sehens. They can be any species, but most Sehens have been starks. The magic warps its host’s physical appearance in a variety of ways, and effects them in other less visible ways as well.

The most well-known biological effect of Sehenautosis is that Sehens cannot gain sustenance from anything but the flesh of other sophonts. In other words, they’re obligate cannibals. They must eat large amounts of flesh, and if this need isn’t met they’ll quickly become desperate, often escalating to violence. They have sharp, wedge-like teeth and a completely reworked digestive system to help fulfill this need (with most other organs not related to this function or the cardio-respiratory tract being atrophied to some degree). Their stomachs naturally produce a thick black liquid known as Mother Ichor, which is one of the most caustic and dangerous substances on the Platform. A certain mass of mother ichor can remove from existence an equal amount of any other substance, destroying itself in the process. The stomach wall is heavily enchanted by the Sehen’s magic in order to keep it from dissolving through their bodies, though as soon as the magic dies, it will take the enchantment with it, meaning that magic removal is 100% fatal for Sehens. Sehens also display some patches of red pigmentation across their bodies, and have low body temperatures and slow heartbeats. They are also unable to lose consciousness (including sleeping) or have their senses dulled in any way. They are biologically immortal, cannot get sick or be poisoned, and have exceptional regeneration abilities, even able to heal injuries like neurological damage if given enough food and time. 

Sehenautosis also alters the way in which Sehens perceive the world. They have intensely heightened senses of smell and taste, and quite good hearing. These traits often cause them to get overstimulated easily and to find certain smells, sounds, or tastes either particularly offensive or particularly interesting. Most Sehens tend to be quite introverted (even if they were not before) and seek to spend larger amounts of time in isolation after receiving their magic. Due to the fact that they spend more of their lives conscious than most, live much longer, and tend to seclude themselves, most (though not all) Sehens end up with issues socializing and reading social cues. Sehenautosis also affects the brain in more direct ways, forming an extreme positive association with raw flesh and blood of sophonts (and food in general), driving Sehens to feel the urge to eat any living thing around them. If they do consume a corpse raw, the magic induces a state of euphoria that can be difficult to get out of and that will permanently alter the Sehen’s brain chemistry. Enough exposure can cause the magic to lock the Sehen in this state, at which point the magic has all control. (Cooking the flesh alters its makeup slightly, which dulls the magic’s response enough to make this effect negligible, and much safer for Sehens to consume.) It is vital that a Sehen receive proper training on how to overcome their Sehenautosic urges, lest they harm others or their own sanity.

Sehenautosis is viewed as the holiest of magics in the Rimea, as it originally belonged to Rimewell Sehe. The Sehen magics that each subsequent Sehen has gotten are clones of his original magic, though it is substantially less suited to starkish bodies than it was to Rimewell’s (hence its substantial degree of warping). However, the main reason that Sehen magic is perpetuated still exists: like Rimewell, those with Sehen magic are capable of seeing Tetracontagon and Quadrilateral as they move about the Platform — something which no other living beings can do. As of 1050, these are all Rimean Sehens that have ever been appointed:

• Rimewell Sehe (565 – 762) – Sehen from birth.
• Octolabrous Adourian (603 – 793) – Apprenticed to Rimewell. Became Sehen at 42 in 645.
• Flossikora Sterling (713 – 775) – Apprenticed to Rimewell. Became Sehen at 28 in 734.
• Alkavire Varlequez (761 – 1052) – Apprenticed to Octolabrous. Became Sehen at 5 in 766 in order to prevent her death from leukemia.
• Ellishiba Adourian (797 – 973) – Apprenticed to Alkavire. Became Sehen at 23 in 820.
• Soyataki Hallia (1002 – 1034) – Apprenticed to Alkavire. Became Sehen at 16 in 1018.
• Blikivallian Hallia (1024 – 1163) – Apprenticed to Alkavire. Became Sehen at 11 in 1035.
• Calleridian Adourian (1037-1217) – Apprenticed to Blikivallian. Became Sehen at 19 in 1053.