Highfather appears in JLA: The Nail, involved in a war between New Genesis and Apokolips, triggered when Apokolips assumed that a Kryptonian shield around Earth was part of a sneak attack by New Genesis and decided that the only way to prevent their destruction was to attack first.
New Genesis is ruled by a being known as the Highfather, a spiritual leader who maintains his people's connection to the primal energy field known as The Source.
One of the few known persons to have entered the Source was an amalgam of Zeus, Odin, Ares, Jove, and Highfather.