Guy Gardener wrote:
There was a tomb.
The Eradicator borrowed in underneath and took the body.
Wikipedia says Kal came back in the 4th books of the Reign of Supermen.
Wikipedia is wrong there. He "officially" returns a few months later, but in the second month of the Reign, he is there watching his monitors. The front of the book read something like "who watches the Supermen?"