The Absolute IS Shar. By receiving the tadpole, all your memories of who you really were have been wiped from you. Same with the others, the origin characters. That's why you are all starting over as Level 1 and why there is literally no back story for the MC. Everything you and the origin characters think you know is lies. Just as Shadowheart THINKS she's actually a cleric of Shar, so Gale THINKS he was a lover of Mystra and so Lae'zel THINKS she was some super awesome githyanki warrior chick who should deserve a dragon of her own and a silver sword, and so Astarion THINKS he's a vampire spawn when really he's not, he's Cazador himself, and Wyll THINKS he's the Blade of Frontiers when the Blade of Frontiers is actually some other guy that is in some snippet of Wyll's memory.
Yes... everyone has lost their memories, and they have all had them rewritten. THAT is why no one questions Shadowheart. It's because deep down inside, somewhere deep in their psyche, the Absolute, Shar, doesn't want them to ask her. It is suppressed. This is also why no Religion rolls are made or information given about Shar to the PCs. It is because Shar is suppressing this knowledge as much as possible so that the MC and company will not divert from her intended course. All of it is Shar's doing, and so when you learn about Shadowheart's secret, whether you know anything about Shar or not as a player, it doesn't matter. It is unspecial to you because it is unspecial to your character because Shar WANTS it to be unspecial.
Mind blown!
And now, to break the fourth wall, ALL of us are in this same boat. We, the players, have had our memories erased by Shar. We once came from Faerun, but WE were captured by mind flayers and had our lives reset here in this world. Shar has taken our memories from us and rewritten our lives. We all THINK we are who we think we are, but the truth is, we're not. We ALL have mind flayer parasites in our heads consuming our true personalities and turning us into mind flayers. WE are all True Souls.
