Kyosuke is smart and evil, but his goal is create a new world ...even if the cost is a war between humans and espers. His feelings for Kaoru aren't clear, he calls her "Queen" but I'm pretty sure that this sentiment isn't love, he just knows that in future she'll die in the same way of him many years ago.
Exactly, Kyohsuke is dead, he's alive thanks the magic, and in order to get revenge against his assassins.
Humans killed him and now he's alive again in order to destruct the world, to breaks the destiny of the espers, that live emarginated from the society. He's very charming, I'm curious of the way he'll follow to realize his ambition.
In my personal opinion, Kyohsuke is the most fashinating characters of the series.
His strong personality and his leadership are two of the major chracteristics of him that girls appreciate very much, like his incredible hypnotic power.
He was a cute and sweet baby and an energic and determinated kid, but after his death, he totally changed, hating the humans.
Now he has a sort of military rank of major in a organizzation called P.A.N.D.R.A., that he joined in order to get his revenge and command the espers like him to the rebellion, creating a war against the humans.
Many female characters are in love with him, but his heart is cold and closed. The only one that knows the real Kyohsuke is Tsubomi Fujiko, his partner in life, when he fighted in a Military Organization with her.
They could be dead but thanks to their powers, they're alive, even if he's a sort of zombie and she's a vampire.
Sometimes Kyohsuke fights hardly against the Children and B.A.B.E.L. (their organization), but when they're in difficult he always goes in their rescue... why?
He likes them, it's clear, but he wants to reach his goal in every way, even going against his feelings.
Humans and espers can't cohabit togheter, and he can't believe that in future this realty would change, because he knows that Kaoru, the most powerful esper, will die killed by Minamoto, a human. This is one of the reasons why Kyohsuke hates Minamoto, but it's not all, he hates the fact that Minamoto loves the three children, especially Kaoru, and they love him, so that adorable girls never follow him, leaving Minamoto alone.