Revelt and Rouven are twin brothers.
Revelt's father was, like him, a very cruel and power-hungry man who saw his children as expendable, so when his wife gave birth to twins, she knew one of them was going to be the successor, but the other would become his father's test subject. So, she sent Rouven to another dimension to save him from that fate, then lied that she had only had one child. Now, studies have shown that twins who grow up separately tend to lead similar lives, so they both grew up to be bespectacled evil scientists who experimented on people. Zill loves magpies.
You know, just 'cuz!