I kept attacking a Chillheart undead Hero, and kept getting 1 shot (my new biggest damage taken is 10k, which is more than my entire HP pool). Eventually I started using a random ranged weapon to take him, down, wondering what this mysterious 1 shot mechanic was, until I found this on him:
It can suck when a hero spawns with a legendary like that. I saw fabius spawn with some blue axe once that kept one shotting my warder friend for 27k damage constantly.when we finally killed him he dropped some blue axe that had a 350% damage WPS, which was quite fun to find out after the fact…