I had no issues with the last boss fight, but I had a Tavern Brawler monk on balanced. After one unfortunate tpk on the run up due to some knock back splash damage, I hasted my monk, dashed, and then jumped all the way to the top in one round. Both boss phases were done in two rounds as the monk action surged and flurried their way through health bars, with the temp member helping clean up with double aoe. The final phase was super underwhelming; it took more time to get in and positioned than to take out it's health. I was really underwhelmed! I'm avoiding monk on my tactician run, and installed a boss difficulty mod to see if I can get things to stand up in the face of my eventual and unavoidable min-maxing.