I always wanted to bring my old Planescape campaign to a proper conclusion. We started when the boxed set came out in 1994, just me DMing and two friends playing. Lots of Sensate philosophy, Egyptian myth, playing with the theme of the "eternal return." Graz'zt was the main villain, but he remained hidden behind a thieves' guild, another lesser demon lord, a fallen deva, the god Set, and a few others. By the time we moved for college, they'd slain the patsy demon lord and were 14th level, but the big reveal never happened.