Jahanamu

The beast from hell, Jahanamu is the lion that usurped Macheo's original pride, the Sun kingdom. He came one day, rallied a bunch of males from nearby prides that were tired of the current monarchs, and charged in head first. They killed the royal family and captured all the lionesses (only missing a few that ran away with prince Macheo); He became the king, no one dared to challange him, he appointed two of the males he trusted the most as his enchmen, and sent the others back to their own prides.

Jahanamu was a tyrant, he took whatever he wanted, when he wanted it; he never had an appointed mate, he just claimed a few lionesses as his, and left the rest to the other two. Rogues and challangers dumb enough to fight him were brutally killed, male cubs would be exiled when they started growing thier manes; and if one of them came back to claim the throne, he'd suffer the same fate. Many tried but none ever managed to defeat the fire demon; what eventually brought about his downfall however, was his overconfidence. Jahanamu wasn't a dumb brute, he knew that even with all his strenght, he needed strong supporters, so when his two enchmen became too old for his liking, he selected their most recent sons, allowed them to stay longer, and had them kill off their fathers when they were young adults, to then replace them.
What he didn't expect was that the two would then start plotting behind his back, planning with the lioness and their own exiled brothers to overthrow him; by the time they were ready the king was starting to get old, with now a whole pride fighting against him, he had little chance; he still fought hard, and had his massive size to back him up, but in the end he had to run away. They chased him for quite a while, wanting to free the savannah from his presence, but couldn't find him without scattering, which would've been a death sentece; so they let him be.

Furious, but still wanting a pride to rule over, the devilish lion remembered of a nearby pride he would often visit in secret to fool around with one of the local lionesses; the Pridelands, so that's where he went. He brought hell with him, it took the combined effort of all the males in the pride, to bring Jahanamu down, and even then it wasn't without casualities; one of the lions that died that day was Macheo, the old king; they had recognized each other and so he was the first to get the full blunt of the brute's charge.