Justin Baldoni, Wayfarer Studios Sue Blake Lively, Ryan Reynolds and Publicist

Justin Baldoni is continuing his legal crusade against his “It Ends With Us” costar Blake Lively — he and his production company just filed a massive lawsuit against Blake, her husband Ryan Reynolds and her publicist Leslie Sloane … seeking hundreds of millions of dollars.

Justin and his company, Wayfarer Studios, which produced “It Ends With Us,” filed the federal suit ripping Blake and Leslie for their alleged campaign to smear Baldoni and snatch away control of the movie … which he directed and co-starred in with Blake.

According to the docs, obtained by TMZ, Blake was “determined to make Baldoni the real-life villain in her story” to deflect from getting publicly trashed as “tone-deaf” during the film’s media tour.

Justin says she was promoting her haircare and alcohol line while promoting a film about domestic violence.

In the suit, Justin says the war between himself and Blake really started back in May 2023 when they started shooting the movie. He claims she was organized a “takeover strategy” as they battled for creative control.

Justin also calls out Blake’s BFF Taylor Swift and her husband Ryan Reynolds for getting involved in the writing of the script. He says Blake had done a rewrite on the film’s critical rooftop scene where the main characters meet.

He says they had a meeting at Blake and Ryan’s NYC penthouse about the rewrite — but he now feels it was more of an ambush. Justin says Ryan was there from the start, singing the praises of Blake’s rewrite, and then hours later … Taylor popped in with her 2 cents, also applauding Blake’s version of the scene.

The docs include emails between the 2 actors right before filming began, and Justin claims Blake “expressed warm gratitude” for all the work they’d done to prepare — but he also believes it was all a facade, so she could wrestle away control from him.

Some of their early battles were about whether her character’s wardrobe — she wanted rich and sexy, but he pointed out she’s playing a struggling small biz owner.

He also claims Blake hadn’t read the book when they were working on the script, adding … “she even tried to Google the color of her character’s hair rather than pick up the book.”

The suit is seeking no less than $400 million in damages from Lively and Sloane.

As we reported, Baldoni is also suing The New York Times for $250 million over the newspaper’s bombshell article alleging he and others coordinated a smear campaign against Blake.