Hollows

General Info
Hollows are a concept that originate from the Bleach universe, as seen here. Hollows are spirits who are unable to pass on peacefully, to be awaited at the Celeteruain gate. They require being dealt with (via special treatment). Those spirits become regretful and they begin to form into a monster, a monster who devours other souls.
 * However, the Iroyia galaxy possess it's own type of Hollows.

Each hollow appears to be based off a type creature, animal or alien. A notable feature of a Iroyian hollow is it's deep yellow eyes.

All hollows wear masks which symbolize something in the spirit's life when they were alive.

The homeplace of hollows are

Hollow transformation types
One can become a Hollow in many ways, such as: ...More to be added soon.
 * Having tons of regret before death, or having enough during life.
 * Committing tons of sins before death, and being not forgiving for them.
 * Giving in, holding onto tons of stress.
 * Being eaten alive by a ton of hollows.

Elimination
In order to eliminate an hollow one must split the hollow's mask in half.