Just blitzed the entire story, some thoughts:
I liked how you reworked Fates to be less "Nohr evil, Hoshido good", and the Burst plot makes a fascinating mystery. Also Corrin is hilariously noob, though good on her for realizing it and wanting to investigate. Side note, doesn't she talk with the Nohr infiltration trio?
tanks
TBF, many tanks were designed for infantry support in the early days, so even if there weren't tanks to fight, they can help carry bigger guns to blow up zombie dragons or something. Though I guess that's what the IFVs were for
Kamui evaporating
da hell did he go? ? strange.

So everything else aside why does Tania have orange hair? I had to scroll through a second time to get the events and locations down in my head but that detail just seems odd and out of place, isn't she still single digits? The son would be the oldest right?

Just realized that Ash's first daughter (Tenia) has the same name as Amelia's first kid. I wonder if that was intentional on their part or just a weird coincidence...

Wow, this chapter was just filled with Weird.

Tenia, Alicia and even Cynthia making an appearance was cute and fun! I'm betting Robin is the strict mom!

Corrin spending her prisoner time to read and learn was great. Her learning tropes to try to not be a naive protag is awesome and funny. Her trying to gather intel with limited sources is still good effort. Her idea to go with army and figure things out is... not that bad. Her getting ganked in the back by Flora, accidentally even, was pitiful and sad, yet still a bit funny. Her being transported to Shirasagi without any prompting or obvious warning was just plain weird. It's as if 'someone' needs the 'plot' back on track or something, eh? eh? Hell, maybe we'll finally see Kamui there too.

That remark about how Corrin and Chrom would essentially fight as auto-combat without a tactician was funny and very true. I learned to never trust the computer after a single battle. In fact Corrin not having enough plot armor is a pretty major worry considering the kind of stupidity the Fates protag gets up to in canon. Still, I do wonder what kind of assistance could possibly be given to her to help with that...

The other major weirdness was the armies and their war supplies, specifically how both seemed to be much bigger and not getting smaller even with how much fighting and dying is happening. If fake soldiers are popping up, surely someone would've noticed already. I guess the source of that interference wants to keep up the aggressive warfare for both sides to continue accumulating casualties everywhere.

Also slightly surprised that some people can still think about escaping the country after the burst, which shows it's not 100% effective even on native populations. Maybe there is hope for peace after all.

Too bad for the ice tribe though. Their sheer distance from Nestra coupled with the lack of Phoenix manpower means they have little options even if they agree to the prices Ash asks for. Oh well, at least they're not conquered, yet.

Global warfare seems to be the current theme, so here's hoping changes occur soon to break out of all these stalemates the next chapter!

Please do more of this...

Phoenix Empire's getting to be like a somewhat benevolent/patronizing mix of America and China.

Hopefully Ash realizes that being 'good' doesn't mean that he also has to be a pushover and let people use him as they please.

Also, is there a reason he's putting his fingers in so many pies? Like, what's his overall goal? World domination doesn't seem to be his thing.

(it's entirely possible this was mentioned already, though)

Great chapter, I always enjoyed your work. I'm curious about what Ash will do and if he'll somehow get another wife XD. The fact that you have several Fire Emblem games happening at the same time is interesting, especially since Fate apparently happened a long time ago in Awakening.

I have to say that I very much like Ash's way of dealing with the invading army. Capturing them wholesale and making use of them as labor while selling off all their stuff, then following up with ransoms for them all, is very reflective of the mercantile way the Phoenix empire operates.

Xander's gambit though, that one I didn't expect since there's little descriptions about how much of his mind was affected by the Burst. At least it explained his behavior in the last chapter, but now that makes me wonder about the other royal children as well.

Letting Corrin get used to the comfortable environment and lifestyle in Nestra sure looks like it'll make her more amenable to simply joining the Empire outright, maybe as a long-term diplomat or student to start with. At least she's happy and acting like the kid she is instead of fighting a crazy war. Still weird how she simply forgot about Kamui entirely. That heroic albino comment was pretty funny though, and might still be relevant if she's needed to end this war.

Flora being given the opportunity and hope to finally be free and protect her home without needing self-sacrifice is nice to see too.

BTW, there's some confusing parts and errors:
"I think they've been reinforced by additional troops from Nestra."
Is that 'Nestra' suppose to be Cheve or something else? because getting additional troops from Nestra to invade Nestra sounds ridiculous.

'Sadly, the Hoshidan royalty travelled with the skill of Dressing Down, pretending to be mere footsoldiers, and their travel to the border was entirely missed by the Hoshidan spies watching the roads looking for finery and large retinues.'

Should that first 'Hoshidan' be Nohrian?

I'm not familiar with FE, so all of this is a surprise to me. Silver lining: everyone on the continent getting mindraped into killing each other makes it easier to conquer? Not that I'd want to settle there, knowing that it's cursed...

What a garbage situation. They should send fliers with speakers blasting trufax at everyone in reach, since it does seem possible to un-stupid people at least. Still, deicide is definitely needed now.

Wow, for Elibe, the amount of tech that's being leaked and integrated usefully by some of these other nations is surprisingly high, specifically by the Etrurians with their focus on rapid-loading crossbows and what looks to be industrial mass production. It's pretty cool to see the changes that occurs after several years of Phoenix Empire's inclusion into these new continents, either physically, technologically, or politically. Those hints for how the next war is being gear up for aren't missed either.

As for Fates-land, Corrin's flaws as a complete newb for a leader was pretty funny to see as a jab towards how the game treats her as one, and totally fitting with her background. Xander on the other hand, I both applaud his quick thinking on how to make the most of a changing situation, and am disappointed in his decision to attack Ash. I honestly thought he was smarter than that, so maybe he just overestimated his own forces. Owell, at least the funny way that Corrin got taken as a prisoner was great for securing one of the mystery twins safely early on. In fact... if this weren't post-burst, I might've thought he did this on purpose in order to let her be captured for her own safety in the well-defended clutches of Phoenix Empire. But that seems to be too ridiculous to hope for even if this weren't post-burst.

Hopefully news of Hoshido returns in the next updates to show what else is happening on that subcontinent, along with info on Kamui.

Thanks for the update, and hope to see the next one soon!

Cheve is... really dumb, like damn son, where'd you get that?

Wow, Xander is quite the little bitch, isn't he? Oh well, I didn't really like the Conquest route anyway. Here's hoping capturing Corrin will lead to her being set on an Ashified version of the Revelation route.

Wow divine intervention bs is bs.

Thank you for your update