Some of you are probably thinking that I'm absolutely insane right now, but I decided to incorporate G5 into my MLP Next Gen AU by making Opaline Twilight Sparkle and Tempest Shadow's daughter as opposed to her being a pony who knew Celestia and Luna when they were fillies. I decided to do this because A) the whole "ancient villain who knew Celestia and Luna over 1000 years ago" thing has already been done B) it gives her more personal beef with Twilight C) It's MY AU and I can do whatever I want and D) Opaline just looks like she could pass as a TwiTempest foal IMO. I also gave her a slight redesign by tweaking her mane and removing those weird braids around her ears because they were too difficult for me to draw. Anyway, time for a backstory!
So in my AU, Opaline was originally named Evening Shade and is Twilight and Tempest's daughter, being Twilight's first foal but Tempests's second as she has a son from a past relationship with the Storm King. Having been born an alicorn instead of becoming one like Twilight, Evening ends up viewing herself as better than her piers. She later got a younger sister named Libra, and while she initially loved her baby sister, she began to grow jealous of her as the years went by as she seemed to get more attention from her mothers when she still hadn't found her cutie mark when other foals her age already had one. While her parents loved all their kids equally, Evening still began to feel that her parents loved her less. After all, they were spending more time with her, by why? SHE was the one who was born an alicorn, not her! Why should Libra be getting more attention when SHE was clearly better than her! After leaving home following an argument with her parents, Evening ends up meeting a scarred alicorn named Caelum (OC brother of Celestia and Luna who I have yet to redesign), who convinces her that she IS better than all of them, and that he can teach her how to be a truly powerful pony.
In secret, Evening trains with Caelum, learning how to hone her magic skills and gradually becoming stronger. In reality, Caelum was training her for when he would one day get revenge on his sisters for leaving him for dead over 1000 years ago, but at some point Evening -now going by the name "Opaline"- catches on to what he was doing and turns on him, using the skills she learned to drain him of his magic and, as she later finds out, his immortality, resulting in his demise. Now more powerful than ever, Opaline returns home and begins to wreak havoc on Ponyville, wanting to show those who ignored her how powerful she was. A battle between her and Twilight breaks out as a result, but Twilight can't bring herself to fire at her own daughter and is struck down from the sky, but Opaline's younger sister Libra manages to defeat her by striking her down with a burst of magic, resulting in her getting her cutie mark. As a result of all the damage she caused, Opaline is banished to the outskirts of Equestria as she was now considered too dangerous to others. Opaline forever hates her mother for this, but Twilight is heartbroken over having to banish her own daughter, and Libra feels some guilt over gaining her cutie mark from defeating her.
Life in Equestria goes on as normal after that, but after Twilight's death from old age over a century later (while Twilight doesn't ascend to Celestia's godlike status in the Barkerverse, being an alicorn DID cause her to live a significantly longer life than most ponies), the magic shield keeping Opaline outside of Equestra finally faded and allowed her back in. Still angry over what had happened, Opaline secretly causes disharmony between the three races of ponies, turning them against each other which eventually results in an all-our war breaking out. Equestria's current ruler Violet Vigil tried to put a stop to all the fighting, but this unfortunately results in her death. In a last ditch effort to stop all the bloodshed, her half-siblings Mystic and High Noon used their draconequus powers to gather all the world's magic and place it into three crystals (i.e. the Unity Crystals), which were then given to the three tribes of ponies. By then the damage had been done as trust between earth ponies, pegasi and unicorns were lost, resulting in the three races becoming divided and going their separate ways.
Then, the events of G5 play out more or less the same: Opaline kidnapping Misty as a filly to use her as a spy, Harmony being restored in the New Generation movie, Opaline trying to steal dragon fire to become a fire alicorn and her ultimately being defeated for good.
