Idea: "surviour mode" That is the thing that had alweys lacked to me in Diablo games. Just get closed in dangerous areas (or exclusively in a dungeon) without ability to run to safe place where you can just restock your health potions, and if something is hard you could alweys grind before the encounter (in hardcore in softcore there is no reason too) so it really doesn't matter how efficient you are, and hardcore also end up in dying becouse of single mistake as any mistake that doesn't instantly kill you is meaningless. The game would have to be balanced for it, identify could be removed, health globes could balance small access to health potions, only hardcore, maybe advancing in hi lvls could be faster, also save&quit would actually save the game as it was when you had left so you could not grind. Dungeon don't have to be endless there is many roguelikes that have end yet even for best players is hard to archive, and nobody can do it constantly. There could also be score board for it on BN.