A/N- Sorry for another update, but I felt like I should tell you guys that the new and improved (hopefully) first chapter is currently being drafted, it'll be a lot longer in comparison to the first chapter of this one, but what can I do? Fingers crossed you guys will enjoy it.
In response to the feedback, I agree that he is OP, I wanted that, but I definitely made him a bit too OP, which is my bad of course, I'll tone it down a little and include some flaws for him to deal with, if I were to make him an anti-hero, it wouldn't be in the mass murderer Uncle Kenny sense, it would be more like bending rules to get what he wants, or straight up ignoring them because he knows that any charges brought up against him wouldn't last at all.
Frieda was meant to be his loveable sidekick in a sense, always with him amd giving him info or advice, but no one else could see her, she'll definitely be there again, but it'll mostly be for talking with him when he needs something, or even when he needs her help, but doesn't ask for it, and maybe a bit of teasing from her part now and again.
Onto Annie, I was originally going to have her as the pairing, but with the mindset I wanted Nick to have, I just couldn't see a realistic way to make it work between them, so I just ignored it and didn't fix it, that's my bad.
Onto Eren and his own flaws, I wanted to make him jealous of Nick, since Eren had trained his ass off to get where he is and then Nick just comes out of nowhere and is up there with Mikasa, possibly better, but at least Eren knew Mikasa was good enough to be top of the class. I also wanted Eren to be angry with him for basically lying about his ODM skills for three years and them act like it didn't matter at all, but that's my fault as I didn't include any interaction between them.
As for bending the story just to fit the cannon, I can only apologise if it didn't seem to flow properly, but I was new to writing and didn't have the confidence to drift too far away from what happened in the cannon events aside from a few deaths being prevented, or something small or miniscule being changed, but that should change in the rewrite now that I'm more confident in my abilities.
As for the comment about the harem, I can see why the story could be seen as a harem, but in truth, it was never supposed to be a harem, it was just meant to be that his options weren't just limited to one specific girl, it was more like, there's the option for most of them, except for Mikasa and probably Annie and Ymir were a no as well. As the story went on, the options were supposed to dwindle until there was only one option for him to sensibly choose. Anyway, that'll be all until the rewrite is posted, so until then!
BTW, if you enjoy cannon changes, OC Ackerman's and/or Frieda Reiss, be sure to check out the other story that I updated yesterday!