Oldest characters in DC

As the topic said. Who are the oldest characters in dc universe?
No cosmic entities or gods such as The Endless, Presence, Anti-Monitor, World Forger, Darkseid etc.
The candidates I can think are as follows
Mordru——older than the universe itself
Ganthet/Guaridans of the Universe——as old as the universe itself
Martian Manhunter——millions of years old
Vandal Savage——thousands of years old
Wonder Woman?(not sure)——thousands of years old per writer's interview

How old is black adam?

That Green Lantern villain Volthoom was imprisoned by the guardians for 12 billion years before he was released so he’s up there.
He was awake and aware that whole time too. Guardians are dicks.

Originally posted by HumbleServant
How old is black adam?

Superman will live to become at least 5 billion years old:
https://ibb.co/hZcH5J4
https://ibb.co/2YFYs1k

No, he won't.

Originally posted by Barron-Ghidorah
That Green Lantern villain Volthoom was imprisoned by the guardians for 12 billion years before he was released so he’s up there.
He was awake and aware that whole time too. Guardians are dicks.

No idea

Atlan the Dead King in both continuities is pretty old.
Kordax as well.
Hippolyta being Wonder Woman’s mother is pretty old.

Mordru——older than the universe itself

This would probably be the best candidate, if you're counting it as compared to current DC-year:

If you're counting it overall, Superman is a good shout, as Galan has shown:

Originally posted by Galan007
Superman will live to become at least 5 billion years old:
https://ibb.co/hZcH5J4
https://ibb.co/2YFYs1k

And under certain portrayals he outlives everything, including Universes: