I posted this in another thread about this problem. Here's my technique: I managed to beat him with a level 32 Sniper Engineer and Vector. Getting Shield Probe helped me a lot when my interrupts and stuns were in cool down. To get him to attack me I went behind him on the platform as far as I could without breaking LOS (next to that circular terminal behind his guardians.). I used Portable Cover + Entrench and then Suppressive Fire (That's what got him to attack without me being right on top of him). When he charged me I used Cover Pulse and attacked him as normal. You have to time your interrupts perfectly to get him. I died a couple of times, but the fight was more manageable, especially with Shield Probe because it absorbs damage for bit if you cant interrupt. Hope it helps