I do feel like I should mention that as much as I enjoy Torchlight 2 I am slightly disappointed with the way it handles many of the boss fights, and that is to say that generally the mechanics (and difficulty) are derived solely from a “Hey, I see you’re trying to fight a boss. Here, have A THOUSAND CONSTANTLY SPAWNING ADDS LOLOLOLOL” design.
Blizzard is better at designing more unique/interesting boss encounters, I have to give them that.