Spoilers within. Beware.
Why do viewers flock to second-rate sensationalism like The Walking Dead or first-rate soft-core like Game of Thrones?
Both shows feature permanent destruction. If a beloved character becomes a zombie on The Walking Dead, that character is not going to get cured. (Conversely, in some vampire fiction, getting cured of vampirism is an option.)
If a character dies in Game of Thrones, I think there is one specific way that character can cheat death – I think one of the gods has a habit of bringing back faithful warriors killed in battle for that god. But most of the dozens of deaths are permanent. (I don’t think white walkers are conventional D&D undead, but I stopped watching that show a long time ago, and I probably won’t resume, so I don’t care.)
The original Utawarerumono has a moderate amount of permanent death. The main characters seem to have excessive plot armor, but some important supporting characters get killed.
One option is to permanently wreck a character’s brain, so that the memories and social status of the character are permanently destroyed. However, I suspect the popularity of amnesiac heroes would make that too easily reversible.
This show is not really dark and gritty. It is not quite a denki-shin show; it is a Shinto-influenced anime that follows the example of Tokusatsu shows like Ultraman. I think the writers are a little bit too much in love with their characters, and the otaku fans will probably be a lot too much in love with these characters.
The combat and the romantic tensions in this show don’t feel convincing to me. It’s a decent show, but its emotional level is stuck at teenager-mode. Even Game of Thrones, which I don’t much like, is a bit more grown-up. Perhaps a better model might be something like Real Drive, in which the emotions are mature and humane, but the sex and violence is restrained.
Anime too often has teenagers swinging sharp steel around with no permanent ill effects. This starts out as annoying and becomes a horrific buzzkill. The converse is that anime should avoid Darkness-Induced Audience Apathy.