We once had a thread about a real antagonist of SoD before SoD was released.
We also have a thread about the Shadows of Amn conspiracy
Let's share predictions about BG3, big and small, serious and lightweight. Let your imagination go wild.
1. Shadowheart, a half
-elf cleric, one of the party members, is a child of Aerie and Charname.
My explanation: During the AMA it was mentioned that events of ToB (among others) will affect the BG3 world. Aerie has a baby there. She's an avariel, and the main character was supposed to be a human. Thus, their child most likely is a half-elf.
Half-elves live about 180 years. BG3 is happening 100 years later than BG2.
Now, Shadowheart is a cleric -> she inherits her divine talents from her mother, Aerie. And "shadow" in the name is a reference to the Bhaalspawn part of her father. Having Bhaal as a grandpa, she can't just be a holy cleric, thus Shadow
This is what we know: "One of Shar's dark disciples, Shadowheart was sent on a suicide mission to steal an item of great power. While wrestling with her faith and strange, untamed magic, Shadowheart has enemies on all sides - and a long-buried secret to uncover". I guess she turned to Shar because of the darker heritage of her father.