Haha! So the short version is we all know Kaneki parallels Arata and even physically resembles him (just like Takizawa & Amon represent parts of Mado for Akira, Ayato fell for Hinami who, like Hikari sacrificed herself to save Arata & her kids, is willing to sacrifice herself to save the Aogiri kids, Urie fell for Mutsuki who leaves him like his father did, etc.) So there’s the Electra complex right there in that Touka marries a man like her father for better and for worse, because he also follows Arata’s path into hurting people. Touka herself says these words:

I want Touka to live up to these words with Kaneki. Still wanting to be with him, but holding him accountable, and I think she will indeed be a vital part of helping Kaneki take responsibility as he vowed to, so that he can eventually make a Judgment about his life.
But anyways. It’s funny to me that “Arata” is the one who stops Kaneki–or rather, the legacy of what Arata became stops Kaneki.

The Arata armor is used to absolutely wreck Kaneki. The Arata armor is a symbol of Arata’s rage, and his desire for both revenge and to protect Touka and Ayato from investigators. This rage and desire to protect is exactly what took Arata away from Touka and Ayato–and Touka says it herself. Because he prioritized these things above just being with them, he lost them.
Kaneki is doing the same thing in the 24th ward when he returns to fight. Arata defeating him and then serving as a catalyst for turning him into Dragon, a symbol of his desire to protect and, to the others, a symbol of revenge even if Kaneki didn’t intend for that to be the case:


And Kaneki himself admits in 159 that he just didn’t want to lose people. Arata was seemingly motivated by the same motivations–out of despair over losing Hikari, and out of a desire to prevent that from happening to Touka or Ayato.
Basically, Kaneki losing to the Arata armor symbolically represented what was about to happen in Dragon: just as Arata lost what he had left for his armor, Kaneki lost what he had left when he became Dragon. Touka’s trauma stems from her father abandoning her, and Kaneki’s actions there caused him to nearly abandon her too even though ironically he was screaming TOUKA TOUKA TOUKA.
But this time, Touka is able to work through her trauma with her father and dig Kaneki out. Time will tell if he’ll be able to overcome the Arata parallel, but I believe he certainly will. I think this is also why Ayato will be important when they eventually deal with Arata: Touka can overcome her Arata-related trauma via Kaneki though I’m sure she will still play an important role when they find Arata; Ayato cannot and therefore probably needs to deal with Arata.



