[quote=@TheUnknowable]1) The appearance says human, not humanoid or Kryptonian, or .  Extremely minor problem.[/quote]I use human to refer to any picture that is not their costumed appearance.

[quote]2) I was assuming they died, but I can change that if you want to use the characters.  Why did the humans give up, though, if two Kryptonians were still alive to fight for them?  Did Darkseid give them Kryptonite poisoning or almost kill them with magic?  Did he wait until they were off-world to attack, then sterilize the world before they got back?[/quote]Just take whatever you assumed they died of and change died to weakened or rendered unconscious.

Or this: Darkseid uses the equation to turn heroes, civilians, and villains alike into mindless slaves. 

[quote]3) She's named "Jessica" throughout the power description.[/quote]Forgot to change that.

[quote]At the end, Lex Luthor and Darkseid both touch it and disappear.  Did it kill them?[/quote]I assumed they ascended to a form of life unbound by the physical, they died, or went to another universe.

The truth: Although it is not made clear in "Destroyer" what happens to Luthor and Darkseid, Dwayne McDuffie has stated that they were both absorbed into the Source Wall.

[quote]4) Also, they are genetic cousins, so kind of incestuous.  It's fine if you don't care, though.[/quote]In the DCAU Kal-El & Kara In-Ze have the same familial relationship as you and I do. The "cousin" thing was pure fiction to help establish Kara's human identity.