The best part about having an evil twin is it proves that you are a good person.*
(The worst part is they try to infiltrate your life and ruin everything in it.)
* I'm assuming that it would be weird to have an evil twin yet be a jerk yourself.
They show up somewhere as an evil version of you, but seem only slightly more unsavory than your regular jerky self.
And they're probably better dressed.
So always try to have your evil twin sit for family photos.
Evil is typically more photogenic, so if you care about posterity more than ethics...
The greatest trick the devil pulled was convincing the world he didn't exist.
The second-greatest trick he pulled was looking fabulous on film.
(With or without red eye reduction .)