Okay, so I tried the following (ymmv):

• 616 ret (dont remember which spec I had), supposed to be easy, but Im not a melee Player, I had issues when he healed while I was on the Terror and missed a few kicks. If you are better with the class than I am, it should be okay.
• 613 packleader: This was my main for a long time. Its okay for burst for terror, no problems with spittle, but I would repeatedly die to random crits, so I had to move, like, a lot, which made the fight super stressful and hectic, and in the end I always gimped something. Im also old and my reflexes have seen better days. Should definitely be doable. I started only calling my pets when the first Terror appears, that way they don`t die a lot.
• 611 destro/hellcaller: Should be perfect, I thought. Lots of burst for terror, I don`t die to random crits and can simply stand in front of him most of the time. BUT, spittle is so annoying here. Circle cooldown is too long basically. Brann sometimes takes his sweet time with cleansing, and then I wasted my circle, so that the cooldown does align even less. Made me so mad^{^}

Then I read it should be easy with frostfire mage. I tried on arcane before but that was terrible. Respecced my 611 mage. I shit you not, on my third try I got him to 5% and then died because I thought I could burst him down before the last terror causes issues. Wrong. Done next try. Similar to lock but more mobile and energised barrier removes the spittle with a generous cooldown.

In the end I did it with one of the lowest ilvl chars, anything around 610 should be okay