Was watching this female barb video
If you jump to 7:15 you'll see a unique mob 'Uzay the Hellion' with the suffix 'Molten'. The barb take Uzay out without too much trouble but like 1-2 seconds after doing Uzay explodes and it one shots the barb! Not sure if this is from the Molten suffix or unique to the mob but if I was playing hardcore I could hve easily been caught off guard by it and died.
hmmm. maybe I should do a few play throughs on softcore first.....