Even before Marvel Zombies, I had an AFMBE/Pulp Zombies "Superzombie" idea in which -- in 1935/36 -- a young Kansas man discovers that he is actually an alien from outer space.
When he investigates the rocket ship he disturbs some corrosion that accumulated while the ship was in flight from whatever world he came from.
He began to be ill and soon died, but only after infecting his adoptive parents and a local country doctor with a Kryptonian "Necro-Virus".
As such the people die and then reanimate with nearly the power and resilience of the 1938 superman (if he had lived or even reanimated -- as it only reanimates humans, it just kills Kryptonians.)
Thus the tormented genius of Luthor (NOT "Lex Luthor" but just "Luthor") as well as many golden and silver age Superman supporting cast must stop the Super Zombies from taking out the last few cities still with a living population -- Gotham (somewhere on the East Coast) and Metropolis (in Ohio) as well as the land bridge between where crops are raised to feed those populations.

Luthor is the inventor of the K-Guns which fire a strange beam based upon an extraterrestrial mineral that seems to have a strong reaction upon the virus.

Still waiting on Beyond Human before I ever try to start writing it up.