Govna is bad

Styling:

Maybe less shadow. Also darker. It's not necessarily meant for aesthetics, but to make the lines be clearly separate from the bg.

I might go for slightly more vertical padding, but it's getting to the point where these are outlier preferences of mine.

Having the Nanoha Narrates style be visually distinct from the normal dialogue style can also help. Whether it's a different color border, a more distinc shadow (already took that option away by starting with a severe shadow,) italics or even a different font, it helps viewers keep up with what's what when the screen starts to get busy.


Timing:

It's very weird. In general you don't have leadin/out, except when you do. I'll make some notes for specific cases to clarify certain timer things, but in general it's all bad and needs leadin/out.

Line 6  Dialogue: 0,0:00:25.90,0:00:27.42,Nanoha Narration1,,0,0,0,,and can communicate with one another.

appears way too early. Needs less leadin.
anytime you want lines to be together, always extend the leadout of the previous line, while keeping the leadin the same. Never extend leadin to meet the previous line.



Line 8  Dialogue: 0,0:00:35.96,0:00:39.92,Nanoha Dialogue1,,0,0,0,,{\i1}Magical Girl Lyrical Nanoha{\i0}\Nwill now begin.

Too early.


Line 23  0,0:03:10.50,0:03:13.62,Nanoha Dialogue1,,0,0,0,,Melodious rhythm, turn into light!

Too early



Line 25  Dialogue: 0,0:03:17.59,0:03:19.99,Nanoha Dialogue1,,0,0,0,,Jewel Seed, seal!

Lasts too long. A good place to cut it would be a bit before that sfx plays.




line 28-31  Dialogue: 0,0:03:48.76,0:03:50.12,Nanoha Dialogue1,,0,0,0,,Someone...
Dialogue: 0,0:03:50.12,0:03:52.56,Nanoha Dialogue1,,0,0,0,,Listen to my voice...
Dialogue: 0,0:03:52.56,0:03:54.73,Nanoha Dialogue1,,0,0,0,,Lend me your power!
Dialogue: 0,0:03:54.73,0:03:59.39,Nanoha Dialogue1,,0,0,0,,Magical... power...

This whole sequence has way too much leadin. Really, you should decide on what leadin/out your series is gonna have, and then give everything the eact same leadin/out. Being inconsistent ends up being far more distracting than anything it could necessarily add to the presentation. Not to mention being consistent lets you work far faster.



Line 38-39  Dialogue: 0,0:04:55.16,0:04:57.00,Nanoha Narration1,,0,0,0,,I'm a third-grader at
Dialogue: 0,0:04:57.00,0:04:59.48,Nanoha Narration1,,0,0,0,,Seishō University Magnet Elementary School, a private school.

While these lines are annoying, getting them down makes for a great watching experience. Try listening for the natural break in her delivery, when you think she herself might be switching the clauses in what she's saying. And that's where you'll naturally put the separation of these lines. (e.g. listen for when she starts saying the name of her school, and treat that chunk as the beginning of the second line.)




Line 78 Dialogue: 0,0:06:32.45,0:06:36.52,Nanoha Dialogue1,,0,0,0,,Okay. Then we'll continue once\NI'm done with school for the day.

Keeping up with what's going on visually as well as audibly is important when timing. Cutting this off early either for the visual cue (the matte rolling in) or the audio cue (the sfx playing) makes the disapperance of the line less jarring. It also avoids having the line look weird and bad overlapping the matte.

Typesetting:


Line 32-35  Dialogue: 1,0:04:14.22,0:04:20.26,Nanoha Title1,,0,0,0,,{\frx30\pos(480,149)\blur0.5\bord0}Episode 1
Dialogue: 0,0:04:14.22,0:04:20.26,Nanoha Title1,,0,0,0,,{\frx30\pos(480,149)\blur3\c&H8352A8&}Episode 1
Dialogue: 1,0:04:14.22,0:04:20.26,Nanoha Title1,,0,0,0,,{\an5\frx-30\pos(484.004,542)\blur0.5\bord0}Is This What You'd Call a Mysterious Encounter?
Dialogue: 0,0:04:14.22,0:04:20.26,Nanoha Title1,,0,0,0,,{\an5\frx-30\pos(484.004,542)\blur3\c&H8352A8&}Is This What You'd Call a Mysterious Encounter?

Pretty good. But try turning on the rotation assist tool (pressing D when you're focused on the video layer) and dragging that triangle a bit. Messing with origin on any curved signs will lead to wonderful things.





"Editing:" I'm no editor, so this is more about line flow and breaking.


Line 66  Dialogue: 0,0:06:07.68,0:06:10.93,Nanoha Dialogue1,,0,0,0,,Good morning, you two!\NIt's time for breakfast!

For lines like these, which are pretty independent clauses, you might as well just make them their own individual lines. It's a preference thing, ultimately.
Also experimenting with stuff like {\clip(204,587,547,704)\t(0,271,(\clip(204,587,726,704))} (like for instance turning the transform into a fbf clip so that it's more accurate) is bad for your health, but loads of fun.





Line 73  Dialogue: 0,0:06:23.64,0:06:25.85,Nanoha Narration1,,0,0,0,,My big brother, Kyōya Takamachi,

Following up with the bad idea from the above comment, you can do a similar transform, but vertically, so that it matches the entrance of the matte. These are all bad ideas, but it kinda fits the mood of the show right now.




Line 96-97  Dialogue: 0,0:07:17.43,0:07:21.97,Nanoha Narration1,,0,0,0,,But in such a loving family,
Dialogue: 0,0:07:21.97,0:07:26.60,Nanoha Narration1,,0,0,0,,I think I'm a bit of a third wheel at times.

It might be worth coming up with a third line, or some addition to the first line, to make this tie in with the cadence of how Nanoha speaks. Basically, while these lines make perfect sense structure-wise, they don't necessarily fit the flow of the audio.





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A great way to get consistent leadin/out is by using aegisub's built-in hotkeys. c and v by default add your lead-in and lead-out values respectively to the slected line. You adjust how much that is under Options > Audio
http://0x0.st/Cd_.png
If that screenshot is dead, just let me know.




I only did half the ep, but this seems like plenty of material. This is by no means a real QC report, since a lot of it I would have been repetitive (more consistent lead-in/out, more mindful of your margins, etc) but I think it's a pretty good starting point.