So, who out there read the latest shingeki no kyojin and blurted an uncontrollable "oh SHIT" at the wait with all the stuff that just clunked into place after this chapter?
Because while I was explaining to the missus (which also involved telling her why I had to wait because I couldn't see a way to make sense of #120 and #121 for her without the context I expected a minimum of in #122.
Instead we get a veritable minefield full of delayed fuse bouncing betties and whatnot, and I am seriously at a loss for finding another author with so much skill at seamlessly and naturally including layer upon layer of foreshadowing, retrospectively obvious yet incredibly satisfying ties and reveals and explanations mixed in amongst the far more obvious details that sat there awaiting explanation from day 1.
Now though?
...seriously, go on... git ter itcha varmints!
Do I need to bang a trash can lid or something?
No?
Ok, here goes.
The prototitan seems like it was stuck in a link with the big weird tree until Ymir found it.
Ymir is a slave who was pre-disposed to treat anything the ancient king Fritz said as not just his right to issue orders, in many ways she seems to display a very similar sort of uncontrollable bond like the Ackerman line ends up displaying--except instead of the forceful invocation of a suitable demand firing off the little lightning bolt effect, for Ymir it seems to have remained hidden that the Founding titan can become bonded like that to those it recognizes as part of first king's descendants--which certain orders and actions of his caused a reinforcing sort of feedback cycle later.
When the memory editing type of effect is used to alter/avoid/end wars during the first Eldian expansion, at some point they encountered the problem of Oriental immunity to said abillities, and possibly there was a deliberate effort or maybe just a pro-Fritz type coincidence where it may have been noticed that even though some of the smaller cross-section of EldianXOriental offspring retained the memory block effects from one of their parents, they seemed to pick up the latent sort of intensely powerful devotion/capability bond which Ymir displayed towards Fritz.
Naturally my assumption is that the family (or families) which displayed this trait were recognized as capable bodyguards who need to be handled carefully so they can be willingly brought into the practice of abiding by/reinforcing various Founding type memory edits, and currently are known as the Ackermans.
In a similar sort of "well, that's gonna be a pain in the ass later" you have the Attack titan, previously stated as consistently uncooperative regarding the same sorts of orders and command structures which other titans who have no such problem being folded into a military force makes it not quite as well suited for applications like large scale warfare. If an Attack user is aiding your side in some conflict it is almost certainly due to the other users influencing this decision, rather than any sort of patriotic drive.
When Grisha was trying to convince the previous Founding holder to help him end this obviously artificial and cruel arrangement within the walls he was struggling over the idea of having to cut off her bloodline entirely, and while she may not have been directly using her abilities on him she certainly seemed to be far better at helping him talk himself out of his plans than one would expect.
In fact the only reason he didn't just flee or give up or convert to her side is because he literally had another Attack user only he could see telling him why he has to do this and countering whatever effect she may have been having on trying to influence his motivations.
When he seemed to be losing his mind and ranting or arguing with nobody, asking why he had to go through this, bringing up his son as though he was taking orders from a little kid, and finally steeling himself for what he had to do in the moment... he was literally interacting with someone only another Attack user could have even known was present.
His other son Zeke being present enough for him to sense and speak to is due to Zeke being a naturally talented ability user, with the royal key to Ymir from the Fritz bloodline, with an Attack user he helped access Ymir's world due to said Attack user also having the Founding latent abilities, and also aided by Eren striving to enable a sort of bridge which Zeke can stand on and look across time at other Attack wielders.
Going back to Ymir herself, if we look at her unusually powerful bond to her king producing a direct influence on the whole grammar/rules/structure of the world where she interfaces with her abilities we can assume that the orders which he gave to preserve her/his bloodline, her abilities, and her role strengthening the Eldian empire could have been passed down to all future Founding wielders.
At some point during the period of probably horrific titan enabled warfare between Ymir's King and the start of the series we can assume that the paths of the Founding inheritors and the Fritz dynasty wandered around a bit and evidently made one of those kings nervous over the thought of losing control over that titan entirely, and so, possibly for the first time, one of the direct royals became the wielder of the Founding titan which produced a no doubt maddening sort of feedback loop: as a royal to whom the Founding user bonds, he is able to give orders and commands with an irresistible strength to the user of the Founding titan, which he apparently noticed included himself, and near the end he was probably losing control as he feared any stray thoughts he had could end up inducing an overwhelming compulsion to see them carried out BY himself.
Seeking some way to maintain control over the Founding titan despite the risks which ongoing titan warfare brought, he must have had a rather literal moment of clarity in which he ordered himself to ignore his own orders with the exception of preserving his people and his control over the Founding titan by keeping the edited memories and walls in place.
Without fully grasping this state of affairs, each new Fritz ruler would come into power with their own ideas and motivations regarding the walls and such, but any such thoughts or drives are smothered by the steamroller feedback reinforcement of DON'T FOLLOW ANY ORDER EXCEPT THIS ORDER TO PRESERVE THE ELDIAN CONTROL OVER THE FOUNDING TITAN BY MAINTAINING THE WALLS that kicks into action once the [Royal:Founding_Bond_Target:Current_Founding_Bond:Self] mental circuit is established, which could otherwise have resulted in increasing derangement as they keep tripping over their own unintentional or intentional orders.
Whew... so yeah, there's a couple more things that make sense now but yeah, fuck that's a lot for now anyways.