User blog comment:Kaestal/My theory of Savitar being the Arrowverse version of Cobalt Blue (And therefore Eddie Thawne)/@comment-24329997-20170415033804/@comment-24152851-20170416103044

Evil =/= insane

So long as villains think rationally and logically they're still very much sane. Insanity only comes into play when they lose their grip and comprehension of what's right and wrong.