The Shar-worshipping crazy goth chick is a great character concept. Trouble is, the game seems to throw a lot of great light-related cleric spells and equipment at us, and all the alternatives seem to be bad. From an RP point of view, Shadowheart obviously shouldn’t be wielding a light-emitting mace, wearing radiance armor, and shooting Faerie Fire and Guiding Bolt all over the place. But I can’t find a lore-friendly playstyle that isn’t substantially worse in fights.
Some of the Shar-related equipment, and the Trickery domain subclass perks, seem to point to some sort of melee cleric build exploiting darkness. But the overall effect seems subpar; for starters, clerics can’t cast Darkness, so another party member would need to supply that, which is clunky.
Any suggestions?
Darkness needs a party that can work with it. The Eversight Ring and Warlock’s Devil Sight eldritch invocation both will preserve Advantage and let you shoot in/out/through it. There’s also a helm very late in the game. As the other commenter was alluding to, there’s a key component here, and it sounds like you haven’t picked it up yet.
I tried this build in my first playthrough and ultimately I wasn’t thrilled with its performance. Darkness is smaller than the big surface spells (Hunger of Hadar, Spike Growth), and a big part of the reason why those spells are so effective is their size. Put most (or all) of your party in Darkness and it’s quite cramped. And not very mobile. I think if I were to try it again, maybe I’d put it in more of a tanky/control build. Combine Darkness with a Ranger’s Entangling, maybe.
If you can handle the deviation, getting Shadowheart out of the Trickery domain would be a big boost regardless. I don’t think War is way off. There’s a mod adding the Death domain, if that sounds any better (though I haven’t tried it).