I find it rather interesting how both Divinity 2 and BG3 had this situation, where one of the last origin characters got shafted rather hard. In the case of Divinity 2, it was Beast, but he later got redesigned and expanded on in the definitive edition.... so here's hoping Karlach will get that same treatment!
Otherwise, it would be a MASSIVE bummer that one of the only unapologetically good-hearted characters ends up with the worst ending out of them all...