I just finished my Korvold deck too, but I built him a little different I think. One of my all-stars has definitely been Feldon of the Third Path Because I'm focusing more on sacrificing just one or a couple creatures creature at a time for value and then reanimating. The fact that he sacrifices at the end of turn is just icing on the cake, but in one game I had a reliable engine using him and Protean Hulk to tutor out a bunch of my value pieces like Jarad, Golgari Lich Lord, Apprentice Necromancer, Apocalypse Demon, and Phytotitan.
Obviously if I was playing in a different group, I would immediately tutor up Melira, Sylvok Outcast and Murderous Redcap, but I don't run the combo.
Reanimating Lightning Skelemental and Phytotitan to Jarad is fun, especially if you're running Stalking Vengeance. Another card I haven't tested yet but I'm sure is great fun is Vicious Shadows