Re: Favorite villain of the trilogy?
Which was the tipping point that made him truly feel like a nobody, which made him realize the potential power of anonymity, which he used to his advantage in the creation of the faux-Mandarin once his experiments started going wrong. Killian wasn't bitter at Tony, he was thankful that he gave him that revelation.
As for his overall motivation -war profiteering from both sides- it was basically the same concept of Stane's, but with a couple little extra layers to it. This doesn't necessarily make it better, but I personally found it more interesting. I think Killian genuinely thought spreading Extremis was a healthy progression in genetics. Plus he was clearly fueling his ego up as he kept rising as a successful "behind-the-scenes guy;" understandable for anyone who was a nobody most of their life (look at so many writers and film students lol). He was power-hungry, all the while sorting out some personal demons. I just really dug that.