It depends. Sometimes rituals are inspired by real cultural or historical practices and then adapted for the story. But in many cases, they are completely fictionalized to fit the narrative.
The Ritual is purely fictional. It was crafted by the imagination of the author or screenwriter. There's no connection to any true incidents or people's real experiences.
The identity of the 'ritual killer' in the true story would depend on the actual case. It could be someone with a troubled past, perhaps a history of mental illness or exposure to extreme ideologies. In some cases, ritual killers have been loners who felt alienated from society and developed these extreme and violent behaviors as a way to cope or as a result of their delusions. Without more specific information, it's difficult to determine the exact person.
The movie Ritual Killer is purely fictional. It's made up to capture viewers' attention with exciting and sometimes fantastical plotlines that have no real-life basis.
The Ritual movie is not based on a true story. It's a work of fiction that takes viewers on a made-up adventure with elements designed to captivate and engage.