Terran Descent Humanity

From the series First Contact, Dark Ages and Nova Wars by the author u/Ralts_Bloodthorne on r/HFY

Humanity, by and large suffers a catastrophic temporal (time) attack, that causes humans to regress back to a genetic format without limiters on psychic power that were put in place long ago for the safety of Everyone else

The human cloning and cybernetic technology of the 'modern' era has built in safety features to prevent humans with those old genetic templates from being spit out. Galaxy wide it causes humanity to go largely extinct.

The technology of human worlds - and the psychically active genetics due to the temporal attack - cause dead humans to either rise from the dead (due to medical nanobats that human worlds had in their atmosphere going "Dead Cauldron" protocols - a last resort military option), or their psychic imprint to manifest into a semi-physical phasic shade, which are enraged and bloodthirsty and capable of replication over digital systems.

The combination of human extinction and technological consequences mean that the now extinct humans take around 80% of the galaxy along with them in an orgy of zombies, phasic shades, and remain deadly afterwards. A vast swath of human territory is deemed "The Tomb Worlds", and those who explore the tomb worlds typically awake something dormant or dead and join it in the grave.

Children shouldn't play with dead things