It thematically bothers me that Shadowheart, with literal 'shadow' in her name who worships and serves the Goddess of Darkness, is a class that 1-12, practically gets zero connection to that theme.

I know mixing caster stats is bad but surely this can be overcome? I'm less focused on melee/range/blaster/support/etc and more concerned with having a thematic tie to her Deity. If at all possible I'd like to keep her first level as Cleric, but instead of Trickster I'd switch her to Light (due to her personal story reasons that I won't spoil).

But the sources of the Darkness spell, or anything similar, are Land(Swamp) Druid3, Wizard3, Shadow Monk3, Sorc3, and Warlock3. Warlock3 seems like the best fit since it'll give Devil's Sight Darkness combo. Great!

Terrible idea, I'm sure, but it's mostly the follow up:

Light Cleric 1 Warlock 3

Then what...??