As a fresh 50 immortal Juggernaut, I was taken offguard over how much of a truck this guy is and how I couldn't do any of my usual tricks due to his buffs. In the end, I got torn to shreds having exhausted anything I had, using a well geared Quinn (which is my usual questing companion since he actually makes me immortal... until this guy <_<), but it just wasn't enough and I died about 6000 hp away from the kill.
Amusingly enough, when I just probe-ressurected and got the chance to get the first attack, he went down very easy. I didn't even use stimulants or anything the second time around, so he was a pushover at that point.
All I can say is... they're meant to be soloable and yes, some of these encounters are tough. What I can say is that this is definately harder than the last story boss, and I really encourage you to do this on your own. These class quests are meant to educate and test your personal skill, and if you can't do it, you're either not geared, preparred or good enough to do it. Remedy the shortcoming and return when ready.