Bradwell always felt as though he never should've survived the Detonations. And, now that he's been injected with the serum inside of Pressia's mother's vial, he's no longer himself. In fact Bradwell sees himself as some kind of monster that shouldn't be allowed to live anymore.
Nope, he's not the happiest dude in the world in Burn. Anything that has to do with the Dome, to Bradwell, is artificial. So being resuscitated with Dome technology makes him (again, in Bradwell's opinion) artificial as well:
"I'm a fairy tale parents tell their children to scare them into living careful lives. I'm not real." (13.44)
Bradwell certainly has the wings to be in a fairy tale... but we get the sense that Bradwell isn't just talking about his wings. He's talking about his whole entire life. He's a wretch, and kids don't want to be wretches. He's also a broken wretch — his parents were killed in front of his own eyes. And now he's a wretch that's been brought back to like via semi-magical means.
His own self-worth can be pretty depressing to read:
"So my life is a mistake; it's only something that was given to me by accident. It's not mine. It's borrowed." (31.27)
He might think his life is a mistake, "given to [him] by accident," but Bradwell means the world to some people, like Pressia. He leads a pretty tragic life to begin with, but his giant wings physically turn him into what he's felt like his whole life: a monster.
You know what they say: if it's handsome like an angel, and has wings like an angel, it's probably an angel. Let's look at Bradwell through Pressia's adoring gaze:
She turns and sees his quick dark eyes, his wind-struck cheeks, the gold tinge to his skin too. The wings are long and ragged—but also muscular and beautiful. (7.51)
Gold skin and long raffled wings and wing-struck cheeks, oh my.
This angelic aspect, of course, is just the glossy flip-side of Bradwell's own fears. Bradwell is worried that he's like something out of a fairy tale—and he ends up looking like something out of religious iconography. He talks about living a "borrowed life"—much like an angel, whose job is to serve as an intermediary between God and humans.
And the religious connotations don't stop with angels—Bradwell definitely has a bit of the Christ-figure thing going on. Just check out this passage describing his death:
His arms spread wide, his hands open—and from one of them, Freedle appears. Nearly lost in the spinning, swirling sheets of paper, Freedle spreads his mechanical wings and takes flight, heading towards the Dome. (64.154)
Whoa. Arms spread wide, hands open? That sounds like crucifixion to us. A martyr's death? Yes, that sounds Christ-like. And a creature that ascends away from his corporeal being and completes his task, even when he's dead? Sounds like Freedle is acting as a both a spirit ascending to heaven and a force that's saving humankind.
RIP, Bradwell. You done good.