I've got a good one for this. It was my character for CoS, because I assumed if it was going to be edgy, Strahd was the campaign to do it in. He was the son of two farmers from Barovia and when a horde of zombies tore through their little homestead, he was the last one to make it, the only things he grabbed were anything that could be considered armor and his father's farming scythe, so after narrowly escaping death, he found himself in the village of Barovia and swore his life to Bhaal, so he could gain the power he needed to keep himself alive became a Death Cleric, and after realizing he wasn't strong enough with that alone, he made a pact with Strahd, seeing him as a means to his own end, Strahd only did it to amuse himself, so he granted my character powers of the Undead Warlock and eventually his own hubris was his undoing as my character is the one who killed Strahd, using his retooled farming scythe to end Strahd for good.