Warning: contains spoilers for Action Comics #1043!
Out of Superman's many different enemies, fans will agree that the most powerful is the mighty Darkseid - but fans may be wrong as a new villain is slowly taking his place. It's certainly true that Darkseid poses one of the greatest threats that the Man of Steel has ever faced, especially considering the fact that it often takes the entire Justice League to even slow him down, let alone defeat him. But Action Comics #1043 suggests that Darkseid, while perhaps strong, is not necessarily better; that honor goes to the mighty Mongul.
In current comics continuity, Superman has left Earth, leaving his son Jonathan Kent to operate as the planet's new Superman. Meanwhile, Clark Kent has been imprisoned on WarWorld without the use of his powers, a metallic wasteland of a planet populated by slaves and gladiators, almost all of whom are eager to claim "iron" (victories in battle grant additional links to their chains, and longer chains denote more powerful and resilient fighters). The entire planet is ruled by Mongul - but how did Mongul obtain his power and his riches?
In Action Comics #1043, written by Phillip Kennedy Johnson with art by Riccardo Federici, an old resident of WarWorld tells the younger inhabitants the story of Mongul's rise to power. The alien who would become the first Mongul began life as a simple, primitive hunter named Guldejo, part of an average Warzoon party. A strange new creature (in reality, an alien observer from another world) looked upon Guldejo with an expression of disgust. This enraged Guldejo, who violently smashed the creature's head in with a rock, killing him.
Guldejo stole the creature's odd armor, which gave him tremendous power. He quickly took over the others of his Warzoon, and none dared challenged him - except his own son, who took the title of Mongul (which means "strongest" in the native langauge) for himself. Every subsequent Mongul takes the armor and becomes stronger than his predecessor. While Darkseid was born with power (and born as the son of King Yuga Khan), the first Mongul had nothing - and in a way, began life even weaker than Clark Kent.
Darkseid is still a well-written character, but he is used far too often; in DC crossovers where the earth or even existence itself is threatened, Darkseid is bound to make an appearance. While Mongul is not a brand-new villain, he is still used far less often than Darkseid. Superman deserves to fight a villain who can pose as much of a threat as Darkseid without that character being Darkseid himself - and as of 2022, that villain is Mongul.