Don't know that he'd really qualify as bisexual...he's really sort of asexual, but I suppose if you come right down to it, he could perform sexual acts with either gender and achieve the same results. I'm not saying he'd enjoy those results all that much, but both genders are certainly on equal ground for him. Quite frankly, if he engages in any sort of actually sexual act, it's because he's after some other goal.
He gets off on sadism and power more than anything. Not that he'd actually perform sexual acts in such a manner, he's just...got some wires crossed. He gets a sort of sexual-like thrill from merely dominating, subjugating, and causing pain, even though there's really nothing physically or even mentally sexual involved in any of those acts for him.
In the case of Kyran, he was using the threat of male sexuality on the War Prince as a method of domination, subjugation and administering pain (albeit psychological). That's not to say he would not have forced Kyran into some sort of sexual act, but his purpose in doing so would've been to heighten Kyran's pain and humiliation, not to achieve sexual gratification. Although, and perhaps ironically, forcing Kyran into a sexual act would have given Iksilon a sex-like gratification...jus t not because of the sex. XD
I didn't really realize how hard that is to explain clearly. I apologize if this is impossible to interpret. >_>