Alterjack, or AUjack, or AUJ, or Alternate Applejack, or in her home universe, just Applejack, was a late addition to the series who came into the main Princess Applejack world after Sunset Shimmer's experiments with her portal mingled with leftover chaos from Fluttershy and Discord's battle. Lost and adrift, she immediately made her way to Canterlot to seek out that universe's version of her. And tear her world a new one for everything it's got wrong with it.
She's tough as nails, she's pragmatic and direct to a dangerous degree, and she's not standing for any imperfections. She's a Princess, and she's the only goddamn one of them who knows that a princess has to do actual political stuff, in this universe or any other.
Thread 175 Edit
After chastising Celestia for her non-existent relationship with the dragons, Alterjack reveals to Celestia that, in her world, she basically controls the new Dragon Lord due to black-mail:
"The Dragon Lord called for a gauntlet to pass on the bloodstone scepter picked the wimpiest, biggest loser of the bunch, convinced them they could be ruler, and then subtly helped them to win the throne. Beat out every other dragon with a bit of 'assistance' and now the dragon who rules it is indebted to us, knowing full well Ah' can reveal who really helped them win at any time, and they'd be torn apart. They place nice, they win a nation. They go against us? Well, you, know."
Assuming that the previous Dragon Lord was still Torch, this characterization goes against his hands off approach as seen in the show.
Thread 257 Edit
 She confronts Celestia, asking why she hasn't done anything all week. When Celestia states she's been doing "self-care," AUJ rhetorically asks: "Isn’t that what stupid rich mares say to make themselves feel better after being complete wastes of time?" As Celestia points out that she is rich, AUJ cuts her off and tells her to do something now or " Ah’ will shoot you with mah’ horn". So, Celestia starts pouring a glass of alcohol. When AUJ says she didn't mean "drink," Celestia states (not in so little words) that she shouldn't have left such a huge loop hole in her words, then. AUJ has no response and Celestia continues by saying she taught her a lesson, which is doing something. She still gets zapped, which prompts her to call AUJ out. Unfortunately, since she didn't get it in writing, AUJ doesn't feel the need to uphold her part and continues zapping Celestia into action.
 Alterjack has a question for Celestia. Celestia gets upset at the mare for interrupting her "Celly bathtime" and threatens to shoot everyone in the castle if she doesn't leave. She also threatens her with a rubber ducky. Not even commenting on any of that, Alterjack asks how evil someone has to be to get thrown in to Tartarus. Celestia relents and tells her that the prisoner must be "suitably difficult to contain or dangerous to hold in a regular cell" and have caused " permanent bodily or magical harm to another". Until they prove themselves redeemed, they'll remain in Tartarus. Alterjack sees the logic in this and asks who's in there. "A great demon named Tirek, who must never be released!" Alterjack asks who else since one guy bing locked there seems a bit much. Celestia reveals that a Bugbear, Manticore, and other dangerous magical creatures are there as well. AUJ points out that they're just animals, but Celestia argues they're dangerous. "Ya’ll just needed a reason to justify havin’ that big area, don’t you?" Celestia reluctantly admits to that, saying the taxpayers would think it's silly if Tarturus only had one prisoner. AUJ fires back, calling her out on their deadliest prison being "a friggen zoo and IT’S ALL YER’ FAULT!" Celestia commands her rubber ducky to "BRING THE PAIN!" and explosions happen in the distant. She claims she herself didn't do that "but consider it a preface to the actual pain I will bring upon you!" AUJ asks if she's going to question the explosion, but gets cut off when Celestia calls on the ducky again, prompting closer explosions to be heard.
 Miles Delight starts out by asking how old Alterjack is. She says her and Applejack are the same age, but he fields a ballpark estimate of "Late 20's? Early 30's?". She asks if he's deaf, but he points out that he doesn't know how old Applejack is. When she asks him why he NEEDS to know this, he basically says he's just making conversation since she's "holding [him] hostage" and it might make future interactions easier. AUJ points out that she's just making sure he did his paperwork right before segwaying into how "annoyin' your 'captor' isn't gonna make things easier" for him. Before she can finish that thought, though, the memory of Rarity annoying her Diamond Dog kidnappers into letting her go resurfaces, leading to her trailing off in silence. Moving past that, she tells him to be quiet and stop distracting her or else the double-check will last longer. When he states that she seems pretty good at multi-tasking, she adds another stack of papers to his workload and tells him to be quiet. Moving on, she muses about how she hasn't seen many major mistakes with his work yet. "Means less work Ah have to make you redo." "Well, I wouldn't want to inconvenience Your Grace with that." And with a loud *Thud* another stack is added to his workload. But, despite a short silence, he's not done yet. "Oh!" AUJ sighs deeply. "It's the glasses." Seeing her confusion, he continues by saying they make her look older. She adds another stack. "You make it work, though. For someone in your 20's." And another. "Are they just a fashion statement?" Then another. She decides to play along and tells him, no, she actually needs them because she strained her eyes "readin' and workin' all the paperwork no one bothered doin' back home". He starts to point out that alicorns have super regeneration, but she cuts him off, saying it has its limits. That's when a thought crosses his mind: "You should stop wearing them." "...I should stop wearing my glasses? The things I need to WORK?" His reasoning is that they're keeping her eyesight poor because her eyes adjusted to them, which messes with her regeneration. "If you take them off, won't your vision eventually heal?" She tells him that's not how it works, but when he asks if she's sure, she just repeats that that's not how it works. "I'm... not hearing a no-" In response, she loudly adds several more stacks to his workload and asks: "Did ya hear that? Did ya?!"
 She asks Celestia to give her one good reason why it's a good idea to keep the Tartarus prisoners in "tiny cages". Celestia can't and says that she's ashamed of herself. AUJ says she should be since "executing them is way easier-" but that thought earns her a hard "NOPE" from Celestia