Dr. Heiter was a well-skilled surgeon and successful at separating Siamese twins. He had a vision...

DON'T DRINK THE WATER...

The man, the myth, the legend

Psychos are bandits who have gone insane with a freakish obsession for the Vault. Shirtless, wearing a white mask and dressed in orange pants, these outlaws can be immediately identified by their homicidal cries, psychotic laughter and constant desire to get into close combat.
Maniac, Lunatic.
Loves killing.

"The lunatic is on the grass*- Pink Floyd

He is exactly the same as the boiled one...but he's really bad at his job. He's awkward and clumsy. He loves Doritos and he says "dude" a lot.
British boy.

The Boiled one (But silly)

What little we see of his actions, PHEN-228 is a malicious entity that actively targets those who come across his path, Rendering people who look at him or hear him into pseudocomas (Paralysis).

Due to his speech in one of the hijacked broadcasts, it's likely he knows what he is doing and is intentionally causing people to suffer from paralyzation.

He is a demonic entity that renders anyone who looks at him into a state of locked-in syndrome.

Manipulative, through both dreams and reality. 