My point wasn't about how good Shadowheart is from a gameplay perspective at all but about how much it makes sense for the purposes of her story...she is devoted to shar so unless something in her story changes, it makes no sense for her to serve anyone else by multiclassing into paladin.
So why can't a paladin serve Shar? Do you think all of the Oaths are somehow incompatible with Shar?
Next, wrong about that. Warlock Fiend patrons are not deities...full stop
Says who? Fiend, deity, po-tay-to, po-tah-to.
If a DM wants to say you are the warlock of a deity but you still play as Fiend Warlock that's homebrew, which DMs are allowed to do but BG3 as a videogame can't accommodate that.
It's all head canon. We can do or say whatever we want. If Larian allows me to multi-class Wyll or Shadowheart as a paladin, then I might just do that. If they don't, I'm fine with that, too. But if they do allow it, as I mentioned, they are implicitly giving their blessing in terms of their notions of canon. Actually, since they are getting rid of the 13 stat minimum for multi-classing, if they allow companion multi-classing, I could multi-class everyone as a paladin.
Warlocks of deities are specifically denotated as such in their subclass like Raven Queen Warlocks...but deity patrons are very rare, and none are in BG3.
Again, you talk of the game as if it exists independently of its player.
