Oddities, also known as alien curses.
They are ethereal and weird alien spectral entities.
The oddities can not be seen by naked eyes, basic senses are meaningless before them.
To sense them directly, one must rely on a Primordial Spirit of at least the Fifth Boundary level.
Alternatively, one can only hope to detect them through the use of magic skills like the Sky Eye Technique if they have prior knowledge of these entities.
Oddities feed on the life energy of living beings, posing a strong threat.
These elusive creatures can inconspicuously attach themselves to humans or other living beings, silently sucking life energy until the host dies.
It is during the moment of their possession that they can be detected.
However, oddities are selective in choosing their hosts, and they only attach to those who let their guard down.
Seldom do these unsuspecting beings notice the alien nature of the oddity in that moment.