Jon Irenicus — Baldur’s Gate II’s primary antagonist — is one of gaming’s most complete villains, voiced by David Warner. His voice work is so effective that players frequently cite the performance as the game’s highlight despite Irenicus spending most of the game as an off-screen threat.
What makes Irenicus’s motivation readable: he is not evil in the service of power. He is in the service of sensation. His soul was stripped as punishment for crimes against nature, and without a soul he cannot feel. His entire plan — stealing the protagonist’s Bhaalspawn heritage — is an attempt to acquire the divine spark that would allow him to feel something again.
BioWare built the villain’s motivation as a tragedy of numbness. Irenicus wants to feel. His crimes are not motivated by greed, ideology, or domination — they are motivated by the specific horror of being incapable of emotion. The game presents this sympathetically enough that players frequently express reluctant understanding for him even as they work to stop him.
Jon Irenicus remains the benchmark against which all subsequent BioWare antagonists are measured — a villain whose motivation generates comprehension without generating sympathy for his methods.

Saved this article for my gaming reference folder. Essential reading for anyone serious about this game.
This is exactly why I love this game. So many layers underneath the surface if you just take the time to look.