I agree with Lanfear, mainly because of Asmodean's own backstory (promising childhood as a musical prodigy that never quite fulfilled his potential)...he was never meant for greatness, only to follow on the heels of greater individuals.

I think one of the Forsaken would have destroyed him and taken the Choedan Kal. I nominate Lanfear first because she was smart enough to stay near him and powerful enough to crush him in Lanfear without an angreal if needed.