Played the update instead of studying, but damn, was it worth it. I think I love Cortez even more now. Also, I can’t believe the secret RO was the blackberry tree all along.
Don’t worry, I never once doubted you 
… Yeah, as much as I can relate to feeling inadequate, I still managed to not become a homicidal terrorist cult leader, so…
Nope not at all
It’s great so far, but i do have just one problem and one suggestion to fix it. The player doesn’t sound old enough. We, the player sound too modern, we learned English (Or whatever you have replacing it) as it evolved into what it is today, there’s no age to the way we speak, i mean think about it, we probably know dozens of languages from not having anyhing better to do while drifting around and there is no way we just stayed in the parts of the world with whatever language we speak. Simply put, we don’t sound old enough, and that is my only complaint. Other than that i have nothing but love for this so far.
I’d think the MC could have picked the modernized version of the language just as well as they’d have learnt a new language though? I mean, why the other but not the one? And of course they’ll then be speaking the modern language with the modern people.
Actually, it’s implied in the game that the player did in fact stay in one place, or at least one country/continent. In the prologue, the player witnesses first hand the changing of power between Regalda and Salgeyd, the purging of magic users, and the destruction of their former homeland, implying that they did stay in that general area for at least a few centuries. Also, even if they didn’t stay in one country the entire time, they probably stayed on the continent and didn’t stray too far from it. I think that’s more reasonable of an assumption to make, given what we know about the PC and the narrative, than that they floated across the ocean to go visit China or something.
Also, assuming that the language spoken is analogous to English, then the PC should be speaking Middle English, which is the form of English that would have been spoken 800 years ago. Middle English, a language that is completely incomprehensible to most modern English speakers, so much so that it’s basically a separate language. Unless you want the author to write all of the PC’s dialogue in Middle English, then I think it’s probably safer to say that they kept up with changes in the language.
Thanks for the update!
Oh my gosh! Welcome back author-san 
This went under my radar for so long, this is great!
I particularly love how my character can have the attitude of “I ran out of F’s to give before you were even a sperm you whippersnapper, permadeath isn’t a threat, it’s a release.”
How though, they never had anyone to talk to. They were pretty much drifting throughout the years.
Also can’t lie, disappointed the secret RO isn’t Charlotte, but some random guy named Flynn.
Hey, I’m not the one who came up with the thought that they’d have learnt new languages. I simply pointed out that learning another version of the same language isn’t any different.
I guess if they could still hear other people, they’d be able to pick up on the development of language over time; I mean it’d be insane to change your vocabulary through just hearing other people’s conversations, but then again, I haven’t spent the last 800 years trying.
Problem is the MC figured they’re never gonna talk to anyone again so I don’t think they’d even try in the first place.
yeah most people certainly wouldn’t, but 800 years of having little to nothing better to do can make you try pretty much anything I guess.
I understand the critique, and logically speaking it’s a reasonable point, but my honest feeling on this is that there’s just not that much I can do to remedy it that wouldn’t take drastically more work, for IMO minimal gains.
As @Titanwithwings points out, true Middle English would be incomprehensible to modern audiences—what I think people are imagining is the kind of English that we spoke a century or two ago, which is slightly antiquated but still understandable to our ears. And that might feel more immersive in some ways, but if we’re talking realism here, it’s still pretty anachronistic.
I mean, don’t get me wrong—I could do that, and people would probably buy into it, and that would be fine, I guess. If it’s not obvious by now, I’m certainly playing pretty fast and loose with the magnitude of gender roles in medieval times, so I’m certainly not opposed to a little anachronism here and there.
But consider that if I changed how the MC talked, I would also have to do this for every single flashback character, while still attempting to preserve their individual voices and speech patterns in a way that easily communicates their characters, which is a lot harder. Making it immediately and visibly clear that Callum is irreverent and informal while Charlotte is a bit more uptight and proper is something that I can do with relative ease by slightly varying the way they talk—but trying to apply those same modifiers to a form of English that is itself different from the norm today sounds like a logistical nightmare.
So while I get why people might want this, it’s just not worth the time and effort to me, sorry.
If it helps, you can assume, like others have, that the MC picked up on gradual language shifts over time, and their flashbacks are filtered through this new perception—which is perhaps a bit implausible, but I personally consider this an acceptable break from reality. YMMV, but that’s how I’m choosing to approach it.
I am deeply amused by the prospect of the MC being driven around in a car, seeing as they pass through all things non-magical.
Will Valerie have to hold on to them for the whole drive just to keep them from floating away? Or will they just kind of be dragged along behind the vehicle by their “tether” to Valerie? 
Assuming tv was invented in your timeline, it can also be assumed that the MC would be spending a lot of the idle time in the last 100ish years watching it. The programming on television is a way many people improve/pick up better language skills, so the MC doing so would be a reasonable assumption as well.
As far as memory flashbacks – multilingual people can dream and think in non-native languages, so it is not a stretch to think the MC would be “translating” their memories into their currently spoken version instinctually.
Tldr version: Your story reads fine the way it is, to me.
Now that I think about it, imagine MC being in a car accident while in one of the cars, that’d be hectic.
On an unrelated note, now I’m imagining MC’s reaction when a bird flies through them. It’d just be hilarious.
1st time: “OH GOD AAH! AH A-… Oh right, dead.”
3498th time: “…Why is this my life?”
IMO it would make even less sense for the PC to speak 1800s style English, since that would imply that they did keep up with changes in the language until that point, but then for some reason they just stopped there and spoke that style of English for the next couple of centuries. So yeah, I think it makes a lot more sense for the PC to just speak modern English. I mean, it’s either that or the aforementioned incomprehensible Middle English, so I’d say it’s the lesser evil. 
Well, they could switch to Old Norse for a change. 
That would be funny.
I mean, is it even confirmed that anyone is speaking English? Pretty sure this isn’t Earth.