
I guess my BG3 custom character headcanons could be de-canonized in-game, but I doubt it, so here's one for Larissa:
She loves magic. She always has. Her parents are both spellcasters (her father a less-obnoxious-than-usual sun elf, her mother a human sorcerer) and she grew up with magic all around her. She's longed to have magical power for as long as she can remember.
...but she's also always been bad at it. Really bad. After years of practice with her father, she managed to learn exactly one(1) cantrip—and while the ability to summon fire felt like a great achievement at the time, she couldn't do anything else no matter how hard she studied, how much she learned, how much she practiced.
But her fascinated study of magic and its lore took on an increasingly spiritual awe, and she developed an intense devotion to Mystra, goddess of magic. She swore herself to Mystra's service and as one of her priests, worked steadily towards greater knowledge, greater understanding of the mysteries of the world, greater preservation of magical lore, and over time, Larissa became one of the sages at her temple.
And she still sucked at magic.
She's personally kind and caring, if a little abrupt, but at heart, she longed to be acknowledged as one of the most devoted, most respected, most learned, most favored of Mystra's priests. Yet her near-total lack of facility with magic made it clear to her that she was not particularly favored.
Still, she continued to faithfully serve her goddess—and a year before the BG3 story begins, Mystra herself appeared to her in a dream and granted Larissa her blessing.
Larissa wasn't sure what that would mean until she woke to light flickering around her hands—and a distant sense of approval and power. She still can't use magic the way her parents can, can't feel the Weave properly: but when she prays, Mystra answers. In her thirty-nine years, Larissa has never felt anything to compare with the sensation of divine power flowing through her, and her devotion to Mystra has never been stronger.
what could go wrong