Falsic

It's a classic problem with fanfic authors. They have an idea that's cool, but they don't want to take the time to build it out. She doesn't want to reveal she's a dragon slayer? Why not? What consequences could matter enough to be interesting. Dragon slayers are novel, but not particularly pestered in fairy tail. There's a plethora of scenarios that could've been built out but that takes time and patience. Those possibilities are gone now

There are a myriad of ways you can go about it. Tired old man who's desperate for peace, mental faculties are failing as PTSD and depression kicks in (after his wife died), subtle hits of Kotoamatukami by his most trusted friend who he keeps letting assassinate him... any of these are valid options. My comment was not a joke. Evil Hiruzen is the laziest trope. At best, I'd say a militaristic 'ends justify the means' hiruzen is a more respectful way of approaching that trope. So let me ask you, are you naive enough to believe the World's black and white?

I got up to chapter 4 but had to stop. The grammar doesn't flow well. The author doesn't describe any emotions beyond telling you that they're happening, and what they do describe doesn't make too much sense. It reads like the author has a list of plot points and is just walking through them. It's like the author is just trying to get to the good part and rushing past the back story.

Why are you so concerned with these questions? Just write the story you want to write. If a suggestion sounds intelligent, engage with it. If you believe it's stupid, don't. Remember, the fanfic community is full of people who've seen it all before. If you allow their cynicism to weigh you down, this fic's lifespan will end at 30 chapters.

It's a cool idea that's too hastily written. The author is well spoken but doesn't grasp basic military behavior or proper escalation. They have Hinata doing so much too soon that it becomes extremely suspicious that she's doing it. No one questions it with any rigor how someone could go from genin level with low prospects to Itachi+ levels of genius. The author hasn't delved too much in the firearms side, but based on everything else, it's looking like they're going to make them for more dangerous than they would be in Naruto's verse. In a verse where the speed of sound is cheap and the speed of light is passable, guns have little place. Between that, not understanding the nature of the Hyuga's relationship with Konoha, a suspicious individual's coincidental interest, and the adult's allowance of an uncertified child to invade the operating room... I can no longer suspend my disbelief. Good luck author. Thanks for the story. I can definitely tell you'll get better on these issues with time. The most important point is that your work is very legible, which is far more than I can say for many fanfic writers on this site.

I'm confused what a gun is going to do in a world where the threats can move faster than sound and, in some cases, light.

That's the DxD fanfic community for you.

In canon, Fugaku is portrayed as the voice of the clan. By the time of the massacre, he caved; he just chose to do so in a way that would cause the least destruction. Hence, why he didn't include Naruto in his plan. He didn't just let Itachi kill him because of love, but because of the pointlessness of resistance. By the time Itachi reached them, they'd lost the initiative they needed to mount a proper coup. Fighting Itachi would only make the ending even more tragic. He even implied his understanding of the deal that was reached. The author for this fan fiction doesn't portray any of these complexities. He only lists Fugaku as an indecisive idiot with a hopeless naivate that shows only incompetence. As for not defending his wife... you're showing blatant disregard for the culture Naruto is based on and Mikotos' own agency. They were aligned as a family unit, going down in the most honorable and practical way they could by that time. She was a jounin, not a civilian; her end would've been the same as his regardless.

The author's twisted Hiruzen into an evil dictator, Fugaku into a indecisive husk, Itachi into an ignorant plot device, and more. There's no nuance to he found. It's impossible to read with the sheer amount of character assassination that's being done here.

Wow, you're really making the Uchiha dumb as rocks. You're really going with the evil Hiruzen route then...