1. They're princes, whose father has been killed.
2. Both have unresolved issues with the fact that their kingdom was destroyed.
3. The hairstyle is in both cases a little out of the ordinary.
4. Both of them have a strong sense of personal honor.
5. Fighting seems to be for them the only thing they are good at.
6. They both attempted to destroy the earth.
7. Both have been presumed death.
8. In the end they end up at the side of the so called good guys.
9. Each of them obsesses over destroying the main character of the show, who is a few years younger.
10. And last but not least: They have the same voice-actor in the American dub.
At first I didn't think about this at all.Maybe because they seem so different from each other at first glance. But then I realized they are both fallen princes and I started thinking about more things they have in common I couldn't stop. Kinda freaky actually.
