Aliens

Aliens (エイリアン Eirian), also known as Extraterrestrials, is a generic name given to beings that live on other planets in High School Ankoku, High School AxA, High School Akuma, High School HxH.

Summary
Aliens are species that inhabit other planets. The exact number is unknown and even their mere existence is unknown. It was only after Riara met Eirian that the existence of aliens was proven in the Underworld, but the Astaroth Clan kept this to themselves.

Moonfolk, although not truly aliens, have been the explanation for UFO sightings for generations. That said they are familiar with aliens and formed an alliance with the Artemeans. This was to fight and defeat the Great Old Ones once and for all.

Appearance
Depending on their species, aliens can take on many different kinds of forms. Although most aliens have different kinds of forms, there are some that appear like humans such as Artemeans and Eirian. Some even have power equal to gods.

Artemeans
Artemeans are a species native to Planet Artemea. They possess an appearance similar to humans on Earth. The Artemeans have some of the most advance technology in the universe, giving them the ability to conquer an entire section of the universe, creating the Galactic Artemean Empire.

Great Old Ones
The Great Old Ones are an ancient race of god-like beings. They are tentacle begins that represent the forces of chaos in the universe. The only known record of them is Lovecraft’s Cthulhu Mythos. They are a complete unknown; even their home planet is unknown.

Trivia

 * The Artemean Empire is based on the Holy Galactic Forthorthe Empire from Rokujouma no Shinryakusha!?