I feel like Unalaq is a better fit due to their shared faux good intentions: Unalaq was supposed to be well-intentioned, but the way he was written made him qualify for pure evil status; Belos thinks he's doing what's best for humanity, but it's made clear in-universe he's a delusional narcissist with a messiah complex. Plus, Belos loses the mask at the end of season two. That said, it was rather iconic.
