Warlords do pretty well with Glowing Guardian early on - assuming you're saving your mana potions for the boss - as they are one of the best classes to take advantage of Humility (being not nearly as reliant on BURNDAYRAZ, HALPMEH, or health regeneration to get high level kills) and can build piety fairly well with courageous kills as a result (and can also take Absolution without having to worry as much about the lost exp). For the boss, you'll generally want to convert to Mystera or Taurog (he doesn't penalize magic use very much, and you aren't casting a large number of spells which is where he nails you) and that usually means foregoing Enlightenment because building up enough piety to convert afterwards is quite difficult.
Dracul actually works reasonably well for Warlords in the endgame, depending on your strategy and available resources, either as a conversion from someone else or even as a brand new worshiper. You can freely give him most of your max HP in exchange for sky high max MP. Again, though, you'll generally want to convert to someone else afterwards (which shouldn't be too hard, since at level 10 you can easily obtain over 200 piety from him via sacrificing HP).
Mystera -> Tikki Tooki -> Mystera should also work reasonably well. Build your piety up to 100, ignoring low level monsters as much as possible, then switch to TT and take his exp and/or dodge boons, kill a bunch of low level monsters, then convert back so you can avoid being penalized for death protection.
I do wish there were more viable ways to stick with one diety the whole way through, but if you're willing to shop around there are a lot of workable combinations. I think it's mainly Halflings (and Priests) who are really lacking in options at the moment (other than Taurog).