Acacius is a Latinized form of the Ancient Greek Akakios and can be interpreted to relate to the same root as the name Acacia, for the thorn bush, or Akakios which means "not evil." With the modern taste for ancient names that end in "us," this obscure but attractive choice may have a chance of new life. Acacius is the name of three early saints.

Demon is probably best left as an edgy nickname or chosen moniker than put on the birth certificate. Typically associated with evil or familiar spirits, it could also be considered an Ancient Greek name, meaning "the people".

Kakia was the goddess of vice and abomination, who tempted others to evil. Basically, a female devil. As a baby name, just....no.

Appropriately used for anime antagonists, not human babies.