When writer/director Josh Boone and co-writer Knate Lee embarked on making the Marvel Comics adaptation THE NEW MUTANTS for 20th Century Fox, their plan was to make a trilogy of NEW MUTANTS movies, each one inspired by a different kind of horror movie. Boone has described THE NEW MUTANTS as a supernatural horror mixture of A NIGHTMARE ON ELM STREET 3: DREAM WARRIORS, THE SHINING, and ONE FLEW OVER THE CUCKOO'S NEST. He hasn't said what sort of horror movies the follow-ups would be, but he has revealed that the intention was to set the second movie in Brazil and have Antonio Banderas as the villain.
First scheduled to reach theatres on April 13, 2018, THE NEW MUTANTS was delayed because Fox wanted reshoots – reshoots that never happened before the studio was purchased by Disney. Disney will be releasing the film on April 3rd, but since the studio merger put the Marvel properties that were held by Fox into the hands of Marvel Studios, it's not likely that Marvel Studios is going to decide to move forward with a NEW MUTANTS sequel. So in an interview with Entertainment Weekly, Boone gave some details on what he had envisioned for the second film.
Referring to the sequel as NEW MUTANTS: BRAZIL, Boone says the villain would have been Emmanuel da Costa, the father of THE NEW MUTANTS character Roberto (a.k.a. Sunspot, played by Henry Zaga). Emmanuel would have been introduced in a scene that was never filmed, even though Banderas was attached to the role.
It was intentional that we didn’t shoot it. We had always planned to have a tag at the end of the movie that introduced the villain for the next movie. We even had an actor cast, but because of the merger and because Marvel owns X-Men now and is going to do their own thing, there was no reason to go shoot it."
… The filmmaker specifically mentions Emmanuel's connection to the Hellfire Club in the comics, which see Roberto traveling to Brazil with the New Mutants to reunite with his estranged archaeologist mother, whom Emmanuel is trying to kill over his own business interests.
Banderas is awesome, but I'm not sure he would be convincing as a Brazilian. It's unexpected that Boone chose a Spanish actor to play Roberto/Sunspot's father after casting a Brazilian actor as the Brazilian character in THE NEW MUTANTS, but maybe Roberto's dad was originally from Spain. Then again, THE NEW MUTANTS has Anya Taylor-Joy playing a character from Russia and Maisie Williams putting on a Scottish brogue to play her character, so maybe the fact that Zaga is from the same country as his character just happened by chance.
Boone said he also would have been adding the characters Warlock and Karma into NEW MUTANTS: BRAZIL, with Karma, who can "mentally possess other beings", starting off as a villain before being
absorbed into the group by the end. We had always wanted to bring Karma and Warlock into the second one when we couldn’t do it in the first one. For us, we wanted that initial core team [for the first movie]."
THE NEW MUTANTS follows
a diverse cadre of teens learning to cope with their superpowers. These new mutants find themselves held in a secret facility against their will and must battle the dangers of their powers, as well as the sins of their past.
Zaga's Roberto is joined in the cast by Blu Hunt as Dani Moonstar, Maisie Williams as Rahne "Wolfsbane" Sinclair, Anya Taylor-Joy as Illyana "Magik" Rasputin, Charlie Heaton as Sam "Cannonball" Guthrie, and Zaga's fellow Brazilian Alice Braga as Dr. Cecilia Reyes.
While Boone knows the odds are against THE NEW MUTANTS getting a sequel, he is holding on to hope that the film will make "a bunch of money so that we can go make the second one."