I'm Beginning to Think I should have taken the Long Way around

So I just tried, for the who knows how many-eth time to kill that evil sonnuvagun. I managed to get off a seven chain, which for some weird reason only threw out the Inferno combo at the end - and then a magnificent twelve chain with my back party, which brought out the wonderful Luminescence combo, something I’d never seen and is so far my favorite. However, while I was switching parties, something popped up under Adrammelech’s action log that I’d seen before... I don’t know why I didn’t pay attention to it. He called up a paling, a shield you can’t see and prevents whoever calls it up from taking ANY damage at all, magickal or physical. Pooh. So I pulled off that wonderful twelve chain for naught, it didn’t do a lick of good. And then, wouldn’t you know, he dropped it just as he called out Thundaja, and again, I was dead.
I’m beginning to wonder if I’ll ever get him.
Maybe I should go back and try and win some more HP first... level up and stuff so I don’t die so easily. But what I don’t understand is that people in forums and stuff are getting this guy at lvl 20 --- I’m at at least 40 for all six of my people... what are they doing that I’m not????