Thanks! I was mostly curious about the out of story timeline to get a better idea of who might regard Vecna mostly as god or mostly as lich. I guess the spoilers involve Kas, the Sword of Kas and the body parts of Vecna somehow (as described in DMG).The ascension occurred during the transition from 2e to 3e.
Technically, he was stopped from reaching his ultimate goal. I won't post spoilers here; the plot/summary is easy to locate if you're interested.