Harbinger - Boss Fight - Ballastre

Ballastre is a Scintilla prophet, responsible for maintaining an anti-gravity field that keeps Harbinger in orbit. However, ever since he was imprisoned after a fall out with the Overlord, the senile genius has gone more than a little crazy. When you have to fight him, Ballastre has reached the peak of his abilities, and no longer knows how to properly use all that energy.

Problem is - once you destroy him, the ship will enter the atmosphere of the nearest planet (Aegis 9) and get torn apart during the descent towards the planet surface. So, once the prophet is dead, you will have to look for a way to get off the Harbinger, and pronto! Thankfully, you never have to get off the ship on your own. The game takes care of that.

When I faced Ballastre at level 28, he did not seem to be too powerful for my human hero. His entry cinematic was the most impressive I had seen so far, though. Curiously, it looked like the sequence was somewhat inspired by the way Diablo appears in Diablo 2... you know, the lowering of three seals, followed by the ground trembling and the boss appearing out of thin air. Ballastre looks almost exactly like the Scintilla Eyons you face before him, albeit much larger in size.

Ballastre - First Look (Click on pic to enlarge)

However, as far as his powers are concerned - well, let's just say I did not have to use a single health pack in the battle. All I did was to pop a health regeneration injection before engaging the boss. His radial attack was too short in radius to do any damage to my hero, and his energy blasts were slow enough for me to dodge most of those.

My weapon was especially customized for fighting Scintilla (2 disruption mod chips, +4 each).

The Gun That Killed Ballastre

Ballastre took tremendous damage from disruption shots. I expected him to have at least some sort of resistance against the type of damage that Scintillas are vulnerable to. However, the way his health bar was going down, I would say he had little or no resistance against disruption. It was only his extremely long health bar that kept the battle going well over 3 minutes.

Disruption Chips FTW - Take That, Ballastre! 
(Click on pic to enlarge)

Bottom line - in spite of the estimates of his power that can be heard from NPC-s throughout the game, Ballastre should not be considered a threat to any character. Just pack your weapon modification slots full with disruption chips, and avoid engaging him in melee. That should do the trick!

Update: Added a screenshot of the gun I used to fight Ballastre.