The daughter of Scott and Barda Free, granddaughter of Highfather, and member of Superman's Justice League. "Our second Kirby-derived character here is the obvious product of the marriage of Scott Free (Mister Miracle) and Big Barda. Barda's strong female genes seemed to have won out in the chromosome game....she is named after Scott Free's late mother."
[Avia's] outfit evokes the armor long worn by her mother as Big Barda while using the color scheme of her father's Mr. Miracle costume.
Batwoman II and Ace II
Batwoman II was fascinated by the adventures of the Earthen Batman so much that she took on an identity like his.
Her companion, Ace II, is a creature of Apokalips. (It is based on Batman's "Bat-Hound" companion during the 1950s.)
Ross decided to give the new Batwoman and her canine companion a Jack Kirby spin. An early Batwoman design was inspired by Morgan Le Fay from his DC series The Demon, and was closer to the original Batwoman costume than the bat-eared design that eventually saw print.
An inhabitant of the Fourth World, who resembles an ancient Japanese warrior.
Alex Ross said that he intended the name and character as a tribute to the work of Jack Kirby, "if Kirby had ever got into a Japanese period."
An insectoid creature. Nothing much is known about the guy.
According to Alex Ross, in Wizard #90, his original idea for Gog was to have him be an "unearthed survivor of the original [New] Genesis/Apokalips planet." As a survivor of that "double world," he'd be double-sized. His face "would be stone, ashen. He'd look like a combination of Highfather and Darkseid.
Incidentally, that's what Orion looks like when he appears in Kingdom Come #2; the beard of his stepfather Highfather, and the body, face and posture of his true father Darkseid.
Information collected from Comicology #1: The Kingdom Come Companion, the Kingdom Come mini-series and the annotations of Jess Nevins and of Mark Waid and Alex Ross.