More Clues

In Uncle Sam & The Freedom Fighters the "Mathemagicians of the Anti-Life Equations" are referred to as Shadow Demons.

During Crisis on Infinite Earths it was revealed that the Anti-Monitor had forced the Qwardians to serve him -- just as several someones have tried to force the modern Qwardians into servitude.

How awesome was it that the tower from Infinite Crisis was made from the Anti-Monitor's corpse? That was wicked cool!