I kinda forgot that the option of being a cleric of Shar is removed too, so I bet if there is any videos portraying players on killing her without Shadowheart probably originates from early access version of the game.
think the main reason why cleric of shar as an option got removed and why she cant be killed without Shadowheart then is probably because its central to the game plot and to avoid breaking apart the permutations the game runs on, like you'd have to add more dialogues under certain conditions, maybe it explaisn why players chosen to be cleric of sharran and engages with Shadowheart had unique dialogues removed too.
Gosh so much of the game needed a lot longer time in the oven to get baked properly, game sure got released too early and certain stuff removed to avoid overwhelming the beta testing process.
