Alright, I'm not very good at explaining things. But I assume the topic in itself is pretty self-explanatory. >_>
I was just thinking it would add to the fun, especially in a roleplaying sense, if you could corrupt one of the good-aligned characters. I mean, there's plenty of redeeming opportunities throughout BGII. Why not any of the opposite? Ok, there is Anomen, but that's making him a maniac, not actually evil.
I'm sure there are plenty of NPC's that could be corrupted. After-all, if you can redeem a vicious Bhaalspawn murderer. Why not corrupt the mind of a poor innocent cleric/mage for example?
This is just a suggestion. I don't intend to actually do this myself, as I have no experience whatsoever in modding. I just thought it would be a cool idea. Feedback would be much appreciated. ;\