According to Cinema Blend, in the Audio Commentary for X-Men: Apocalypse, Bryan Singer has (or might have) revealed that one of the villains in the yet to be named Wolverine 3 movie will be Mr. Sinister. So whose Mr. Sinister?
Okay folks here how this goes. Comics, like any other media, has a lot of ups and a hell of a lot of downs. With comics there’s this interesting trend, something that is drawn real cool but the writers and artists tend to have no clue what to do with the cool drawing. Mr. Sinister was one of those cool drawing that came in the late 1980’s in a comic called X-Factor – Marvel’s first attempt to bring Jean Grey back and reunite the original X-Men. Mr. Sinister ordered a group called The Marauders to murder a group of sewer dwelling mutants called Morlocks in a storyline called Mutant Massacre. Why? I’ve read it a few times and I don’t have a clue. Later on it was revealed that Mr. Sinister was this scientist named Nathaniel Essex from the 19th century who had real wood for evolution, knew Mutants were coming and for some unexplained reason was obsessed with Scott Summers (Cyclops) and Jean Grey (Phoenix). Why? Again, this is not clear and has been changed over the years.
Mr. Sinister’s powers keeps changing depending on the writer. Sometimes he’s a shape-shifter. Sometime he has telekinesis and telepathy. Sometimes he fires energy out his hands somehow. Oh, and somehow he either hired or tricked Gambit into leading the Marauders even those Gambit did not appear in comics until many years after the Mutant Massacre event. The point is Mr. Sinister is a villain with no focused goals who keeps popping up siding with every villain for unfocused reasons. Oh, and he also created a clone of Jean Grey named Madelyne Pryor who Scott Summers married then left when Jean Grey came back to life. This cause Madelyne (who did not know she was a clone of Jean Grey) to become a demon villain called Goblin Queen for. . .reasons.
Now the truth. Mr. Sinister was created because Chris Claremont wanted to create a new villain because he was tired of constantly going back to the Brotherhood of evil mutants. While Claremont was one of the best writers on X-Men until Joss Whedon and Grant Morrison did it better, he created Mr. Sinister at the time when it was clear he was over staying his welcome on the series. (Seriously, he make Storm a child and had her being hunted by vampires. I shit you not.) Mr. Sinister is a dumb villain who has dumb plans and they keep bringing him back because he’s a cool drawing. The reference to Mr. Sinister can be seen in the final scene of X-Men: Apocalypse on a briefcase with the words “Essex Corp” on it. What Mr. Sinister will be doing in Wolverine 3 is not clear, but neither is the actual plot of the upcoming movie. The reason I went through the confusing explanation is to demonstrate that this may not be a good thing, even if people think it’s a good thing for some reason. We’ll see how this works out.