I don't own any canon characters.
Time seemed to slow down as Zira charged. All eyes were on her, she knew, but now she was beyond caring. Ahead, Simba looked shocked for a long moment, then came forward to engaged her, just as Kovu had done with Nuka not so long before.
Nala, seeing Zira's charge, tried to come forward with Simba, but he blocked her, unwilling to let her take blows meant for him. A moment later, they met.
At the last moment, Zira leapt, and there was enough force behind it, helped by the fact that Simba had risen on his hind legs to meet her, to bear the great lion over onto his back. Not that things stayed that way for long, as he swiftly threw her off, and rose to meet her attack.
The fight between Simba and Zira wasn't the only one going on, of course, because a moment after that fight started, Nuka judged his chances, and attacked Kovu again, who'd turned away from him to watch the fight. It didn't last long though, because as soon as it started, it was noticed, and within moment, both Vitani and Kiara raced over to put a stop to it.
The rest of the lionesses, both former prides, looked on in various states of shock, worry and disbelief, both at where Simba and Zira were fighting, and where Vitani and Kiara were stopping the fight between Kovu and Nuka, by the simple expedient of the latter being pinned by his own sister.
"Are, are you alright," Kiara asked Kovu, as Vitani pinned Nuka.
"Yeah, I'm fine," Kovu replied, though he looked the worse for wear. "Vitani," he then asked, worried a little about his sister.
"Go, now," Vitani replied, And Kiara and Kovu wasted no time in retreating to a safe distance.
"Vitani, what are you doing," Nuka asked, struggling, but unable to throw his sister, "you're letting him get away."
"I know," Vitani said, "and as much as I'd like to kill him myself, I'm afraid I can't do it, and I can't let you do it either."
"Why not," Nuka asked, "why can't I kill him, he betrayed us."
"It's hard to explain," Vitani said, "but I just can't let you do it." She waited a moment, then relaxed a little, and said, "I'm going to let you up, on one condition, don't try to kill Kovu again, understand?" Nuka nodded, and she allowed him to rise, then they turned to watch the main fight.
Simba, despite his larger size and greater strength, was having trouble , both because Zira was lither and nimbler than he was, and because Zira's strength was not merely physical any more, but was driven by a spirit of pure anger.
Slowly, the fight, and the fighters, moved closer and closer to the edge of the gorge. The warning shouts from the lionesses either weren't heard or ignored. All to soon though, the situation became apparent, and there was a moment, right on the edge, when both Simba and Zira stopped fighting, in a feeble attempt to steady themselves, and prevent themselves from plunging into the gorge.
All was in vain though, as momentum carried them over the edge. Every other lion and lioness raced to the edge and looked down. There was relief for a moment, as both Simba and Zira appeared to have come to rest safely on a small ledge, some way above the roaring deluge below.
The relief only lasted for a moment though, as Zira, trying to regain her footing, slipped, and went almost completely over the edge, only just catching herself in time, and even then, she was slowly slipping.
Simba raised his head blearily. He'd come down the slope hard, and only dumb luck had saved him from himself plunging over the edge. He shook his head, trying unsuccessfully to rid himself of a throbbing headache. He spotted Zira, slowly slipping over the edge, and his mind worked furiously.
This lioness had tried to kill him, and here she was, slowly slipping to her death. Kill her, said a part of his mind, throw her off, let her fall, she'd do the same to you.
You're not her, said another part of his mind, you're better than her, give her a chance. Half obeying, Simba shifted his weight, and reached out with a paw, claws extended, and gripped one of Zira's forelegs.
Zira cried out a moment, but Simba held firm, as did his claws, and she stopped slipping. Looking up, she saw the conflicting emotions on his face, anger, sadness, pity, hope even, and suddenly she couldn't stand to look at him.
Zira slashed at Simba's face, which caused him to back off, and convulsively release his grip on her foreleg. No longer braced, she suddenly slipped backwards till she was hanging, by just her claws right on the edge.
"Zira," Simba called down to her, extending a forepaw "give me your paw."
"Never," Zira shouted, and slashed, leaving three cuts on the pad, and smiled when Simba cried out a moment at the pain. She cried out herself though, as she felt herself slip further down the edge, as a result of having lost her grip for a moment.
"Zira," Simba called, ignoring her last slash, and extending his paw again.
Zira looked up into Simba's face, but she could still not bare to look at it. "Farewell, Pridelander," she called, let go of the rock, and plummeted.
Simba was stunned for a moment, but then scrambled upright, threw back his head, and roared, in anger, pain and loss. A moment later, the rest of pride roared as well, each seemingly unaware of any other doing likewise.
The roaring died off in a few moments, but it was long enough. As each lioness stopped and looked around, they suddenly became aware of the others again, and realised what was going on.
Two of the group didn't roar however, and those two were Vitani and Nuka. They, like the others, had raced over to watch the final moments, but the death of Zira, the closest figure in both their lives was stunning.
As Simba began to ascend the cliff, back to the plateau, Vitani began to return to normal. She nudged Nuka and said, "come on, let's go." Her brother didn't move, so she gave him a shove, and said again, "come on, let's go."
Nuka raised his head, and looked at Vitani, his expression unreadable, but frightening. Suddenly something inside him snapped, and he shouted, "traitor," and clawed her face.
There was further silence and motionless, as Nuka looked at his paw, claws extended, and blood on them. Vitani, likewise, reached up and brushed her muzzle, where her brother's slash had opened fresh cuts. Looking at the blood smeared on her paw, she looked up at her brother, stunned. He matched her gaze for a moment, then turned and fled, as several lionesses approached.