Japanese voice, for reference:
http://youtu.be/JKMYe-1QJWw

Weil is the main villain of Zero 3 and 4, and appears at the very end of Zero 2. For this role, I want a German accent. The Major in Hellsing Ultimate is a good example. (https://youtu.be/o8C9jJNif0A) Since he is German, Weil would pronounce his name "Vile". Since this is an old man, he must sound convincingly old, with a decently deep range. He should have a raspy tone to his voice, but he shouldn't sound weak.

Appears calm and manipulative, but underneath he is clearly psychotic. He is also highly intelligent, gaining power in Neo Arcadia by rebuilding Copy X, and staging a fight between Copy X and Zero, making sure Zero would win.

He is extremely sadistic, having enjoying caused the mayhem of the Elf Wars, and desiring to rule all of Neo Arcadia, humans and Reploids alike living a living death for his revenge against both of them. He is also power-hungry, believing the joy of ruling over people something only a human could ever understand. He seems to be fully aware of his villainous nature, going as far as calling himself the devil in Z4.

He views Reploids as being inferior to humans, that they should obey them as if they were their slaves, however he holds Omega in far higher regard than even himself, never viewing him as a servant. He also hates ideals, believing them to be worthless, as he was the one who started Project Elpis, a plan to combine the Mother Elf with Omega to control all Reploids, going against X and his plans of coexistence.

Weil's biggest weakness is that he underestimates his enemies, firmly believing there to be no way Zero could defeat Omega, so much as challenging anyone to stop him when he gains control of Ragnarok.