If You Can't See the Heavens, You're Buried in Hell

For humanity's survival after an asteroid destroyed part of the ozone, scientists made three Celestials, lab-created creatures with heavenly fragments.

Astral, part star, will prove they're more than "just the stars". The public loves them, or at least acts like it with their fan mail and cheering crowds. Once Astral's new artificial ozone brings back the stars from the history books, surely Astral will be valuable.

Selene, part moon, does anything the scientists tell her to. Even if that means destroying Astral's ozone. But once she realizes the scientists aren't as moral as they claim, she's determined to find and prove her own independence. So what if that involves letting humanity go extinct?

Helios, part sun, can never seem to control his anger issues after a lifetime of routine "tests" from the scientists. He's convinced all humans are evil until he meets Ben, a child newly orphaned by the ozone explosion. As they bond, Helios decides he'd do anything to protect Ben, including stopping Selene.

Astral, meanwhile, must figure out another way to be remembered. If Selene and Helios utterly needed them, that'd be a good start.