I have two more tasks for you (unfortunately, neither necessarily involve the Codex). So here goes:
Task 1: defeat Namtar's Lair with the Orc Warlord. I do not specify god or anything, however there is one prep you must take: the Bear Mace blacksmith prep. Good Luck!
Task 2: raze Vicious Steel using an Elf Assassin. For bonus points, do it with the Vicious Token.
In either case, if you try it and fail miserably, let me know, I'll give some more pointers, I just don't want to spoil the fun beforehand!