I want to highlight the uncanny voice of the “Asynchronous Rondo” boss in the Side Order OST.
The boss’ appearance is based on a panopticon prison. It was originally created to help save the consciousnesses of people who have been “sanitised” (Torn apart and mixed in a giant blender (yes, really)) in the previous game, but it now acts as a literal prison for those same people. The voice you hear is actually trying to sing a hopeful tune from the previous game, but you might not realise it until the 3rd or 4th time you encounter it. When I realised it for the first time, I was disturbed and at the same time impressed by the thougth that went into this relatively small part of the game’s sound design.