Bondrewd

Bondrewd, with the subtitle the Lord of Dawn, is the arc villain of the Idofront arc in Made in Abyss. He is a White Whistle and is considered by the others to be cruel and evil.

Biography
A long time ago in the past, Bondrewd was convicted of an unknown crime, with a bounty placed on his head, and became a delver of the Abyss, as well as selling drugs to fund his Abyss research.

He would stop at nothing for this research. To test out the Curse of the Abyss, he sends dozens of orphaned children up to the surface (remembering all of their names). The most notable of these atrocities is what he did to Mitty, who was turned into nothing but a horrifying blob that could not speak, but was still self conscious and only acted on instinct.

He is a body surfer, having used dozens of infected-people's bodies throughout his life, akin to Dante (FMA 2003).

Eventually, he trapped his own daughter, Prushka, in a cartridge, still alive and conscious in a similar way to Mitty, but she can spill out of the cartridge. This is considered horrible by the entire main cast.

Despite this, he appears to genuinely care for the children he destroys, showing a caring side to Prushka and is genuinely proud of Nanachi.

Trivia
He has been compared to Shou Tucker for his horrific deeds on children, and his memetic status in the fanbase. The key differences are that Bondrewd is not Pure Evil due to genuinely loving the children he experimented on, and that Bondrewd operated on a larger scale than Tucker.