At first I tried a bunch of advice about keeping my distance and using ranged stuff etc. but because I had created a dual wielding NB it just did not work for me as it did for others.

In the end I did the following
- first part hitting with swallow soul & blood craze to get him down while self healing. Roll dodged his jump attack and his hard attack.
- Just hit the titans a couple of times as I hadn't realised blocking was just as effective.
- For the long haul I triggered Leeching Strikes then used swallow soul, blood craze and that while sticking close to him until the end. He never seemed to fire the ranged attack at me as I was right on top of him at all times.

The wife is a Sorc and she basically kept moving and using her destro staff, used bolt escape to avoid hid critical atacks, death blocked the titans and then continued the above tactics until he went down.

I used a restoration staff, with the following on the skill slots: soul trap, haunting curse, steadfast ward, force siphon, and clannfear, with ultimate set to panacea. It worked far better than I expected Thanks to the temporary massive ability powerup, I didn't even have to block the titans, I just used the staff on them and they died quickly.

I like using the clannfear, because every enemy attacks it when I summon it, and (temporarily, at least) ignores me. Molag Bal was no exception.

*** Yes, I know my post is 7 years after the previous, but some players (myself included, just now) found this thread useful, so I thought I'd add what I learned to the thread

you guys talk about the main quest line or the one at imperial city sewers?

Oh boy, we have another thread necromancer...