Deoan sounds very made up and middle-ish evil. If you want something evil, go with Damian, Dorvian, stuff like that. If you want non-evil names, go with Jesse, Joey, Charlie or names that sound cheery.
Here is a link to a name generator to help you come up with names, too!
Good.
A good name for an evil twin sister is Similia, sounds like similar, like a twin, yet has an evil twist to it.
raid
Devil
Both of Goku's sons are heroes; i.e. good. Therefore, Goku's evil son has no name, as neither of Goku's sons are evil.
Mephistopheles is another name for Satan, the personification of evil.
Mephistopheles is another name for Satan, the personification of evil.
No
Dr. Evil right?
There is no such thing as "good evil." Evil is the opposite of good.
Mephistopheles is another name for Satan, the personification of evil.
Agathokakological