User blog comment:FairyRaven/Fairy Tail Chapter 465: 400 Years, Review and Commentary/@comment-114.108.214.205-20151209150638/@comment-4829046-20151210082127

To showcase that some Psychopaths don't care about grand schemes, loyalty, wealth, authoritative power or control, just destruction, carnage and annihilation.

For me Zero has always been one great psychopath. Plus he was beaten with raw Dragon Force via magic Jellal possibly gained from Brain, and not typical BS, so he ranks higher than most other villains imo.