My current build, it can be modified better for the fight but I use this anyways and i never die. Here's what ya need:
Redundant Fibber x2 Slagged Rubi DP Unkempt Harold Bee or Rough Rider 50% Vitality relic Legendary Class Mod (It's still possible but harder without the Class Mod) and patience
It's not the fastest way but it never takes no more than 5 minutes to kill him.
I gunzerk the Redundant Fibber on both hands, and the Slagged Rubi on the right with the DP Harold on left. If your using the Bee keep firing the Fibber until you get hit then switch to the Rubi+Harold keep shooting and shooting till the Bee is regenerated fully then switch back to the Fibbers. Repeat process till dead!
If you are not going to be serious, then I'm not responding. I have a Norfleet. A real one not that modded crap. I run out of ammo after only taking off a quarter of health.
I'm 100% serious. The video was legit. I can produce similar results. Sorry you can't believe that. It's the 11/5 in Immolate, 5/5 in Reaper, and Maliwan Allegiance relic that makes the Norfleet do so much damage. The only hard part is keeping Terra slagged, he has fairly high resistance so it wears off pretty quick.