Who is He/What Has He Done
The cruel conqueror Mongul once roamed the cosmos aboard Warworld, a planet-sized engine of destruction. Invading countless worlds, Mongul enslaved entire populations. Dying at the hands of Neron, his son carries on the family tradition, most recently as a member and would be leader of the Sinestro Corps.
Mongul was the ruler of his people, until a revolution occurred and he was forced into exile. In Mongul's first appearance he kidnapped Lois Lane, Jimmy Olsen, and Steve Lombard and threatened to kill them unless Superman gave him the key to Warload He retrieved the key and mentally linked to Warworld's controls. He attempted to kill Superman and Supergirl, but he was ultimately rendered unconscious due to the mental strain of hooking his mind up to Warworld. Mongul manages to escape before Warworld is destroyed.
Mongul then attempts to conquer Prince Gavyn's homeworld, Throneworld. Mongul kills Prince Gavyn's sister and forces the prince's love to marry him so he can take the thrown. He blackmails the resident planets to submit to him with Throneworld's planet-destroying weapon. Superman arrives and battles Mongul while in the meantime Gavyn shuts down the weapon, forcing Mongul to retreat. After this defeat Mongul desires revenger against Kal-El. He kills a Controller and steals the Sun-Eater to devour Earth's sun. The Legion of Superheroes and the Justice League battled Mongul, but it was futile until Superman finally defeated Mongul while the Legion of Superheroes destroyed the Sun-Eater. Mongul who at first appears friendly yet intimidating. After giving a brief tour of WarWorld, Mongul describes the process of how the commanders planet is being destroyed and the population being abducted by robots sent from WarWorld as they speak. The police commander is horrified by the turn of events that have taken place, and is then brought to a strange room were there are hundreds of heads on pikes, the commander questions Mongul about the room and Mongul explains to him that "all these heads demanded my surrender", then Mongul rips the police commander's head off.
Mongul a is warlord and an adversary of Superman.
I should say yes.