Halfas

A halfa is the term for a mortal-ghost hybrid. Due to the duel nature of their biology, halfas are able to shift between a human and ghost form at will, and have abilities on par with high level ghosts.

Creation
A halfa is created when a human's genetic structure is infused with ectoplasm. The conditions for this may vary, but it generally requires a human to experience a high dosage of energy combined with massive and rapid ectoplasmic exposure.

Not all humans can become halfas: the only humans who can survive the process are ones who have above-average resistance to ectoplasmic exposure, which can be inherited or built up over time.

Biology
Halfas share biology of both humans and ghosts.

History
The first known instance of a halfa was Vlad Masters.