User blog comment:NinjaClockworker/Kayo Sudou...What Happened to You?/@comment-155.69.203.3-20121024061408

Well, if Body Swap does,you know, swap bodies, then Lukana resided in Elluka's original body. It is unknown whether Lukana is still alive due to residing in Elluka's body, or dead and Elluka's body has rotten.

The same thing probably happened when Elluka used Body Swap with Kayo. Kayo is now in Lukana's body.