For those not familiar, Annihilation was a Marvel event from 2006 written by Keith Giffen. It was a story that highlighted several of Marvel's space-focused characters, many of which were rather obscure. I thought it would be a fun exercise to come up with a similar story idea for DC's space characters, with some restrictions.
* No Kryptonians or Daxamites. You can use other Superman related characters like Mongul or Maxima.
* No members of the Legion of Superheroes.
* No characters from the Emotional Spectrum.
* No New Gods characters.
* The only characters of Earth origin you can use are Adam Strange and Captain Comet.
* The only Thanagarian you can't use is Kendra Saunders.