An Addonexus is a creature of lore that is originally human at birth but if they are born on the day of a solar eclipse and when the Halley's Comet is in the sky they become gifted with abilities after they exit the womb. They have a substance that is infused with their blood that hold magical properties. Addonexus' are able to control pure energy which also allows them to control the elements if they master them. Addonexus is most easily able to master the elements of light and shadow. Addonexus' also have the ability to use the blood substance to control their bones and use them as weapons. Being able to have their bones penetrate their skin at various locations including the elbow, hand, base of neck, back, forearm, knee, and calf. They also have the innate ability to see people's natural aura and with this they can stop the person from using their natural element. They can lock on and determine their emotions and can heal people's physical wounds.

Most people who become Addonexus' do not find out and do not experience any unusual physical aspects until they reach the age of about 12 or 13. At that age they begin to feel their bones move under their body, begin to see spiritual auras, etc.

Addonexus' do not age normally like people do however they do age. They age about 3 times slower than normal humans do so if the actual age of one was 45 they would look 15. As an Addonexus gets older the difference becomes much smaller but sometimes poses a problem in one's early life because the parents of a Addonexus may wonder what is going on with their child. They are also hard to physically hurt because they can heal themselves surprisingly fast.

They are only capable of living 75 years at the most because since they are born when the Halley's Comet is in the sky and they will die on the day the Halley's Comet comes again in their lifetime which is always 75 or 76 years apart. When that second comet appears it might be the birth of another Addonexus.