The first time I built a pyro Qiqi I was only able to get her to deal a bit over 305K damage (but hitting 3 enemies at once so if you want to add those up and call it over 900K I won't object). Years later she's doing more than 8 times the damage with today's hit for 2,511,657. The boss can provide another 5 buff stacks if the curse doesn't kill off the team so there's still room for improvement but I'm happy with the 2.5M for now.
Author of Typica software for coffee roasters.