Raphael Brown is UNLOADING on his estranged wife ... calling her a violent, manipulative stripper -- a monster who's engaged in a vicious campaign to smear him ... according to court docs.
Brown filed a CRAZY 250 page document in response to accusations made by Juliette Gil-Brown ... who claims the former Next singer beat her on multiple occasions, even when she was pregnant.
In the docs -- obtained by TMZ -- he argues his wife has gone off the deep end ... flying into a jealous rage after she saw pics of him on vacation with his girlfriend.
-Juliette's own mother told him "the devil had taken over [Juliette's] soul" adding, "she's crazy."
-His wife changed her Facebook status to "widowed" after threatening to slit his throat.
-His wife verbally attacked a female fan on Facebook, telling her to "stay the f*** off my husband's page" ... even though the fan is a cancer patient who enjoys his music.
-Juliette (who's not Black) goes on racist rants on social media, calling him "a dirty n****r" and saying he's "the reason n****rs" are dying of AIDS."
Brown goes on and on ... denying he's ever been abusive to his children, noting he even got temporary custody of his then 7-month old son when Juliette was in jail. He also denies looking at porn around the kids, calling the accusation ironic since she's a stripper.
We called Juliette for a response ... and she told us, "He is a dirty n****r ... because he fits the stereotype of what a Black, ghetto person is." She also claims her mother can't stand Brown and would never say bad things about her to him.