Sienna gets an unstable hedge wizard career. Upon using any magic either ult or staff, she immediately dies by explosion, forced to spectator with no chance of rescue, and a chaos spawn is spawned in her place.
I’ve already done that one:
Pirate/Priest of Manaan Saltzpyre: Saltz reveal that his real name is Saltspite and that he is the lost brother of Aranessa Saltspite
Bardin Gorkson: Bardin get empowered by the Greenskin God and become a Night Gobbo
My money is, and always has been, on Nude Kerillian.
Barmaid Sienna; she gets Dual Steins and Mop as her new weapons - the latter is a staff that splashes bloody, boozey water from a bucket onto enemies. Her ult will be her just kicking enemies in the crotch while screaming that they’re drunk and to get out.
Druchii Slaver Kerillian. Gets whips and increasingly flirty dialogue with Kruber.