It could be explained that the change in personality was the result of him being possessed by Haddo, or whatever the bodythief Aleister Crowley guy was called. Though that was a guy who'd gained immortality through the serial possession of his followers, leaving them trapped in his old shell while he made off with their wives and fortunes.

Huh, just realised that Voldemort's obsession with immortality could make sense in the LoEG-verse due to Haddo's astral battle with Mina combined, with Jack Carter shooting his physical form, making it impossible for him to continue his cycle of serial possessions.

Though this probably means that they'll be treated to a panel or scene of Voldehaddo attempting to molest Hermione or something at some point, as that WOULD be in character for Haddo. *annoyed sigh*

Huh, I wonder if Harry Potter is the Moonchild that is the focal point of the Century series?