What is the work?[]
Gnosticism is a series of belief systems but the main core of it is that the physical/material world was evil and that the purpose of mankind is to reach a level of spiritual enlightenment (i.e. hidden knowledge) or that the gods in the mythology would take pity on mankind and try to save them from the Demiurge.
Who is he? What has he done?[]
Yaldabaoth, or the Demiurge, is the false god of the physical world being used as an explanation for the theological conundrum The Problem of Evil; to describe Yaldabaoth, he is in some ways the god of the Old Testament where all of the reprehensible atrocities he commits in the OT is there to differentiate between him and the God in the New Testament.
In some versions of the myths, Yaldabaoth was the son of the higher goddess Sofia, the personification of wisdom. While many of the higher beings in the myths wanted mankind to reach a level of enlightenment, Yaldabaoth allows atrocity after atrocity even if it means keeping mankind in the dark about spiritual matters as long as he was worshipped for all time. In some of the myths, he also tries to usurp his mother Sofia, often going as far as to kill her. This would lead to her remnants becoming intertwined with human souls.
Freudian Excuse? Mitigating factors?[]
None. He wants to be worshiped as the supreme god in the Gnostic myths not actually caring for his creations rather relishing in their mindless worship of him.
Heinous standard[]
Like I have said, Yaldabaoth was invented to serve as a means of explaining the Problem of Evil and why God seemed to be a different character in the New Testament. In Gnosticism, Yaldabaoth is behind all of the evil that happens in humanity as he designed the physical world to be evil, contrasting him with Sofia and the other gods who granted man souls and knowledge of the spiritual world. Yaldabaoth would rather keep mankind blind so that it would be easier to lord over them. Toss in matricide and you have an all-out disgusting false god.