Drossel's unaware that he has lost his humanity, that's what's left of him is just being sustained by stuffing of wheat. He's exceptionally loyal to who he believes is his master, even stumbling with his stuffing falling out to inform him of Grelle, Sebastian, and Ciel's invasion of the manor. He works hard to fulfill what he believes is a request to turn anyone into a doll who had come into contact with the Shard of Hope, but this turns out to be him over-zealously trying to please his master. The person in control of him, though, belittles by calling him "incompetent." Additionally, he was never saddened by his doll dying. Drossel has a tendency to describe people in terms of what materials he'd use to make their doll form with, then singing different verses of "London Bridge," occasionally writing his own lyrics to describe said materials. Sebastian later reveals that this song, combined with the music Drossel plays, is used to control the dolls he crafts. Drossel's probably based on Herr Drosselmeyer, the toy-maker from The Nutcracker. In the Making of Kuroshitsuji II, his name was misspelled as "Drocell Caines."- Drossel is Christadelphian, meaning that he believes God's the creator of all things and the Father of true believers, that he's a separate being from his Son, Jesus Christ, and that the Holy Spirit's the power of God used in creation and for salvation.
Grelle reveals that the real Drossel Keinz had his soul seized by the Grim Reapers five years ago, indicating that he was dead. At some point, his body had been reanimated with a temporary soul and he attempted to go back to work for the Mandalay family. However, his master, Duke Mandalay, had been committed and abandoned his manor; he wasn't the person controlling or relaying orders to Drossel. - After discovering that he wasn't human, but actually a doll, Drossel longed for his humanity, as it was the only life he knew. Although, after he regained painful memories of his human life, he's rather conflicted about how he now feels about it. Drossel cares about his dolls — very much so — in what could be called a 'brotherly' or even 'fatherly' way. Drossel committed suicide at the age of 22 by throwing himself into the Thames. His death occurred mere weeks after that of his young sister, as he was so riddled with grief and guilt that he thought the only release from his torment was death. Although he'd jumped, his death was slow as his mangled body lied on the rocks for hours before he finally died. He vividly remembers dying. Drossel should've become a shinigami as punishment for taking his own life, but Angela interfered. Drossel was a proficient in archery as a human as he learned these skills from his grandfather. Likewise, his grandmother taught Drossel how to sew from a young age. He's been sewing since.