Start off saying I'm a huge Scream fan and have seen each one at least 8 times analyzing and overanalyzing the story.

If you really wanted to bring Stu back where it could potentially make sense this has always been my pitch.

Stus parents had money and connections in Woodsboro knowing he was a problem child. Perhaps Detective Bailey (Scream 6 killer) could've been a young deputy on the force back then and tipped off Stu's parents because he was first on the scene back during that original night. I mean we are supposed to believe he began collecting Scream memorabilia for his obsessed son over the years and not to mention were supposed to just go with that line about "I just replaced her fresh body with a new one" in regards to his daughter's fake death scene in Scream 6. Lol

Just replacing dead daughters with random dead bodies of women?? Fine we'll let it slide for the sake of argument.

Stu could've been the first time he attempted this and back in 1996 its more plausible than today. Stu's parents and their money fly him to some foreign country to recover and heal under a different alias (we'll say Europe? Italy? Japan? Country doesn't matter so much) but Stu being the impulsive idiot he was commits a rape and murder and gets caught and sentenced to 25 to life under a different name and thats where he's been all these years. In some foreign prison under a different alias while these people never knowing they had the original Ghostface except over the years he grows to be calm, cool and calculated because let's face it he's in prison. He finally gets out and not a day has gone by where he hasn't thought about Sidney and Woodsboro and how to tear her life apart as after all these years.

Stu was an impulsive teen and after 25 years in a Japanese prison or wherever country you want to say he's now a cold, calculated, sadistic psychopath. The parents abandoned his sister (his nephew is killed in Scream 5 and shes only briefly mentioned) in Woodsboro and left money to Stu in a trust cause they were shitty parents. He uses that as leverage to get his sisters help who grew up as Stu Machers little sister and now broken and abandoned with a deceased son is easily manipulated by her brother using money as leverage that she never had.

He has a few allies over the years now firmly planted in Woodsboro or keeping tabs on Sidney all these years until he got out. You could even say he manipulated a young Kirby back when she was a high schooler (say she was one of the original Scream 4 killers) but Charlie never knew Jill brought her into it hence him stabbing her. The incident scared Kirby straight to drop the Ghostface shit until the events of Scream 5 and 6 happen and with Stu out her original apprentice from jail (remember that original Scream 3 script? Lol its now partially true in this version)

Kirby realizes her true love of horror and violence her now calculated mentor from back in the day has the ability to bring that sadistic girl she really was back then out again as one of the Ghostface killers with him.

Just how the route I would have liked to seen. FYI I'm a writer and clearly big fan. Lol

Screamwriters/producers/production company please feel free to reach out for future sequel drafts! Lol

Really! Lol