It's cute these guys are still writing letters. In our generation where texting is the norm seeing formal written messages like this is a little foreign and makes it interesting. At least to me.
And it's a good thing they do because if it wasn't for that we wouldn't have the bombshell of a lore reveal that we got.
So Kaeya's secret is out. I mean first anybody who thought Kaeya was a royal - myself included 
- has now been proven wrong. The message was pretty clear. The Alberich Clan are not royals. That said they became regents when the real king weakened. I think I might have a theory on that.
But the thing that's much more clear cut is the mystery of the eyepatch. For the longest time there's been a ***spiracy theory going on about that patch. What's hiding behind the covered eye of the Khaenri'ahns. Now this still doesn't answer for Dainsleif and we also saw no eyepatch on Halfdan. If I had to guess I'd say the patch was originally ceremonial for the Alberichs in honor of King Irmin. Anyway Kaeya's not even blind in that eye but it's like he's keeping it on both for his old Khaenri'ahn purpose and also to keep reminding Diluc about it lol
Meanwhile this whole event quest is just a look back at Diluc: Year One when the Dark Knight went on his earliest patrols. And I have to say I'd take Adelinde over Alfred any day! I also love the supporting cast. You have Commissioner Varka, his "daughter" Jean "BatGirl" Gunnhildr, Detective Eroch, Lucius Albedo, his therapist Dr. Alice Thompkins and of course his bff District Attorney Kaeya Dent. O and of course we're Robin. 
I do find his batsuit to be weird though. He's got his dad's Delusion gauntlets on, his abilities look different as a result and the suit itself has a p***ing resemblance to a Fatui Pyro Agent. But at no point does the story even talk about the Fatui just the Abyss. Even stranger is how the story only talks about his ongoing battle against the Abyss but even the letters are referring to his history with the Fatui because it's their Delusion gauntlet that killed his dad.
Maybe we haven't seen the last of our Dark Knight Hero. 
Tips and Tricks from a Super Casual Genshin f2p
