If you believe director Bryan Singer, Hugh Jackman's upcoming and final performance as Wolverine will be quite sinister.
Audio commentary from the recent digital release of X-Men: Apocalypse has Singer telling X-Men fans that Mr Sinister will be a villain in Jackman's last Wolverine movie, which will arrive in theatres in the northern spring of next year.
This clue from Singer was already hinted at in a post-credit scene at the end of X-Men: Apocalypse when suits from Essex Corp, a company owned by Nathaniel Essex, aka Mr Sinister, one of the most popular villains from the comic books, gathered mutant blood from a top-secret facility.
Mr Sinister debuted in Marvel's X-Men comics in the 1980s and is obsessed with genetics. He's particularly fond of mutant genes and the many powers those genes possess.
Mr Sinister is a big-name bad guy for Jackman's Wolverine to go up against in his final movie but may not seem like the right match for those fans who may have been hoping for another brotherly showdown between Wolverine and his half-brother Sabertooth, most recently played by actor Liev Schreiber (although Sabertooth could make a surprise appearance).
Fans should also hope Sinister's potential inclusion in the last Wolverine movie goes better than the last time a major X-Men villain appeared on screen.
Oscar Isaac's blue makeup in X-Men: Apocalypse couldn't cover up an interpretation of a classic X-Men villain that probably should have been left to CGI.
But considering Jackman has said frequently that this will be the last time he pops his adamantium claws for the camera, Sinister could help 20th Century Fox find a replacement for Jackman's Wolverine for future X-Men films.
As a villain obsessed with genetics, perhaps Mr Sinister could bring a Wolverine clone into Fox's X-Men movie universe.
Currently, in Marvel comic books, the mantle of Wolverine is being worn by a young female mutant named Laura Kinney. She's a genetic clone of Wolverine (though she pops two claws out of her hands instead of three like Wolverine) and for years has been very popular. She's headlining her own "Wolverine" comic book series at present, and rumours persist that she could have a future in X-Men films.
A female clone could be the perfect replacement for Wolverine in the movies if Sinister's arrival in Wolverine 3 involves the villain playing with Wolverine's DNA.
But it would be foolish for Fox to try to replace Jackman's Wolverine so quickly. This isn't a Batman situation where you can announce Ben Affleck is the Dark Knight shortly after Christian Bale ended his three-picture reign.
Even Adam West will tell you, when it comes to Batman, the suit is doing most of the work for the actor. Jackman has never put on a mask for Wolverine, despite the character frequently wearing one in the comic books. His performance as Wolverine is right up there with Robert Downey Jnr's Iron Man and Heath Ledger's Joker as one of the best superhero movie performances of all time.
You don't find someone new to fill those shoes and wear those claws right away.
But that doesn't mean the character of Wolverine can't be a part of new X-Men movies once Jackman is gone. And Laura Kinney wouldn't be burdened with comparisons to Jackman.
Just because Jackman is hanging up his claws doesn't meant they can't be put to good use by someone else.