There are few possibilities that can be viewed as "difficulties" that can be chosen in-game.
First we had the view of you being a servan of one Pretender, trying to help him in the Ascension Wars by killing one, or all!, of his enemies.
Then there is the possibility of you trying to become a pretender yourself. This would not give you the benefit of help in the beginning, and would not give you any powers faith or the pretender you are serving might give you.
You might also be trying to kill/help the Great One, but (s)he would just be a pretender-powered entity that succeeded once a long time ago, and this isn't really that different.
We also have had some ideas for vaults and special Places of Power. Magic sites defended by appopriate beasts and creatures is one, nation-spesific levels another, well known players is interesting (:-o !) but hard to do and might not be worth the effort. Of course, Gandalf's Random Circus would be intersting...
If Ed would be to implement many of these, the game would most probably need a world map. And a world map would have to have different terrains in it, from plains and fields and forests... to underwater!
Also, as I said earlier, newsgroup:rec.games.roguelike.developement has much of discussion, and people, that would probably be more of help to Ed than we. And many ideas that, if he sees them, might make him want to implement them and rewrite to game only to discover the next one and the find another and... So, let's not tell him about that discussion about 3d-dungeons implemented in ascii by different colors...
Also, I think if and when Ed gets a nice list of spells he should post it in this forum and let us rip it apart before he implements them. What is thematic, what is not, what "colour" should each spell be... Options are many. I am not going to post my half-a-dozen ideas I have had after I read the list of what, 30?, spells before the work is well going... Ed has enough pressure on his shoulders as is!