In Lekë, the Ni-Seraphi are the mortal enemies of the Mystics. They appeared in Lekë through the Wrinkle in the Sky. Since the end of the Time of Tears, Ni-Seraphi only occasionally come through the Wrinkle; they're weaker than their predecessors and in far fewer numbers. The Royal Guard typically patrol the Wrinkle 24/7 to dispatch of any Ni-Seraphi as soon as they come through. Still, should you encounter a Ni-Seraphi, here is what you need to know about them to survive an attack.
Adult Form
In their fully matured adult forms, the Ni-Seraphi appear as colossal-sized, beautiful angels wrapped in silks. Their skin is extremely pale, and their hair is silver. Their eyes swirl and are silver like mercury. They bleed mercury-colored blood that's got a thick consistency and is very warm. Adult Ni-Seraphi have poor eyesight and, due to their size, they do not move fast. However, they are durable and have a few tricks up their sleeves:
◈ I. They communicate with one another through singing.
◈ II. To compensate for their poor eyesight, they use their singing as a form of echolocation.
◈ III. A Mystic's aeonheart releases a unique signal only the Ni-Seraphi can hear. Even with their poor eyesight, they can sense the general area of where the signal is coming from and then using their echolocation singing to pinpoint exactly where it is.
◈ IV. Their Hunting Melody is known to instill fear in their prey (Mystics), which makes it easier for Ni-Seraphi to find Mystics whose bodies react out of fear (heart beating more rapidly, stronger signal, etc.). Mystics who have learned to stay calm when they hear this melody are harder for the Ni-Seraphi to track.
◈ V. Adult form Ni-Seraphi can sing to produce orbs of sound, which they can shoot with concussive, explosive results.
◈ VI. When a prey has been incapacitated for feeding, adult Ni-Seraphi use their mouths to create a strong funnel of air that acts as a suction. This sucks Mystics into their mouths like a black hole. It is difficult, but not impossible, to escape this suction current once you get captured in it.
◈ VII. Ni-Seraphi prefer to consume Mystics alive, as a dead Mystic means a dead aeonheart,which is useless to them.
◈ VII. Seraph's Kissed Mystics, due to having a second aeonheart (The Kiss or The Mark), are particularly vulnerable due to producing a stronger signal that attracts Ni-Seraphi more than the typical Mystic does.
◈ IX. Because it is challenging for an adult form Ni-Seraphi to capture Mystics on their own (it's like trying to capture an ant with a bear trap), they use their spawn to seek out and incapacitate their prey who might be hiding.
Pupa and Larva Forms
Ni-Seraphi at their Pupa stage, spawn out of the adult-form Ni-Seraphi. In their Pupa stage of life, they are human-sized and wear darker-colored silks, though notably taller than your average human and more willowy in body structure. Pupa have very small wings (barely even noticeable), and glowing crimson eyes that allow them to see much better than the Adults, including in the dark. Although Ni-Seraphi reproduce asexually, adult Ni-Seraphi appear more feminine, while pupa appear relatively more masculine-bodied. The pupa are faster, more agile, stronger, and more nimble than the average human. But due to their human-size, they are relatively easy to kill, like a normal human is. When you kill a pupa, their bodies don't turn to stone like their adult forms, but rather, they decay rapidly until they're nothing but a strange sulfuric-smelling pile of brimstone. The pupa are designed to bring prey out of their hiding spots and incapacitate them so the adults can feed on the Mystics alive. The pupa also have a unique predation skill where they can extend their pointer finger like a really long thin needle, with a glowing pointy tip at the end. They attempt to stick this long pointy needle-like finger through a Mystic's heart. It doesn't kill the Mystic, but releases a toxin to paralyze them for a few minutes.
Ni-Seraphi in their Larva stage, spawn from the Pupa. They are small like cherubs, but the most grotesque and ghoulish looking. Larva have many different looks to them, but they're all pretty ugly, deformed, and bird-ish in nature. They torment their prey by clawing, biting, and harassing them. The Pupa control the larva and use them as "hound dogs".