I have a question about Krieg before I decide what build I want to use when I play as him. His Hellborn tree looks interesting, but it seems borderline unusable on higher levels. Given Krieg's preferred playstyle seems to be buffs while having shields down and/or on fire, it seems that on higher levels* (where Fire damage is pretty much fatal), the self-immolation will lead to near-instant "Fight For Your Life", even at full HP. Or is the self-immolation damage much lower than what enemies can normally deal, where it's more of a nuisance (like Pyro Pete's DOT) as opposed to fatal (pretty much every Fire attack).
*By higher levels, I'm talking mid-to-late TVHM and beyond