I’m not so concerned about the source of Beck’s powers, but I do want him to be the villain. He’s a con man at heart, so I really want his story about being from another dimension to be a lie. I’m hoping that the destruction caused by the elementals is a cover for robberies or some such that he is committing.
Maybe he just wants to be seen as a hero so he is setting up these attacks so he can defeat them.
I have heard some stuff that says Mysterio may be more psychopathic here then he is 616 Spider-Man comics, but that is a characterization we see from Mysterio in Daredevil, Old Man Logan and his crossover into the Ultimate Universe, so this has shown up on the page before.
The problem is in the Spider-Man comics, Mysterio stories are often about his gimmicks rather than deep characterization.
Also, it could be that Mysterio does not care if people die while he sets up fake stunts to make himself look heroic, it seems the stunts themselves are a goal, he can gain more fame and money by presenting him as a public hero, then could simply using these stunts as cover for petty robberies. If he is a public hero, he could get a bunch of endorsement deals, why risk that with some petty crimes?
I always feel like making Mysterio's motive greed is a mistake, most Spidey villains are greedy, that is a pretty basic motive. For Mysterio. greed should be a secondary motive, for him the primary motive should lust for fame, Mysterio's MO makes far more sense if his goal is fame rather then just money.
I actually think psychopathic glory hound is the path I would suggest for him if Vulture had a sense of honor, Mysterio having none is a great contrast and Mysterio's willing to endanger human lives is a bigger stakes affair then him just robbing a bank.
The fact is someone can be a con man and a murderous psychopath, those are not mutually exclusive concepts.