Is this a proyection of Held mind, like a hidden culpability sentiment; or another thing outside Held mind (like a nigthmare) ?

Oh look, it's lunchables Valiant!

That's where the nightmares in her head started.
She will still wish to help protect herself (letting the nightmares out in the process), but some time later she realizes what she did, loses interest in developing her magic due to that, which further lets nightmares take control finally in the Heaven arc.
And Theobold will slowly realize she is slipping into resignation and he has no way to help. This will make him sour to the point he breaks down and finally land in the prison to tell the story.

I think its a manifestation of Held's guilt. She waited day after day by the mailbox for word that Valiant had been found. She's moving on now but a part of her mind hasn't let go yet and in this dream world its able to create this scenario where Valiant is blaming her for being left behind.

@oskarloko
I'm not sure, but I'm guessing the latter? Held seems surprised in panels 2 and 3, and while she does seem to have some misplaced feelings of responsibility, she's pretty actively been trying to fulfill her "responsibilities" by trying to get to Vallance. As for the incident itself, it was a lot more active and crisis-like to Held than the passive inaction "left to rot" implies. Also, there doesn't seem to be any suggestion that Held could have sacrificed herself in Valiant's place, nor that she thinks she could have, nor that she feels guilt or regret. If it were an authentic sentiment of Held's manifested, I expect it would prey on her intense sorrow and grief, trying to incite hopelessness or MAYBE going for a survivor's guilt angle specifically by suggesting that it was a tragedy that she lived when Valiant died. This seems more like some malevolent entity taking a shot in the dark; even if it does originate from Held, I bet it's some fear of manipulative people, her memory of some initial concern that the fairy was using her mixed with the fear of people using her in general.

@oskarloko Likely the guilt clouding/distorting the memory, the same way the backgrounds are, or the technomancer ghost had a black bottle in the back.

It is not a nightmare in Chernyl's nightmare sense because Chernyl could bring those nightmares/thoughts to "life" as in to bring the to the material world.

It is as life itself, if we see the world through the eyes of selfishness we see kindness as having hidden ill intent. Guilt is that that makes us feel responsible of our actions, yet we can feel guilt due to the actions of others.

Emotions shape our mind and thoughts, like a veil does to sight.

...The fact that he's holding a giant cartoonish stick of meat makes this whole scene completely ridiculous.

Have you expected to be gamma-irradiated or what, Valiant? Dead things tend to rot otherwise, just deal with it.

Also, he's holding this piece of meat in order to make a demonstration?

@oskarloko: I'm thinking it's a nightmare generated by an intruder.

Oh, it's one of THOSE hallucinations.