Quimang'a last stand with henches?

Tried to finish the damn quest for 2 hours now and no go :/ Even got to Ran Musu and got myself three lvl 10 henches. Still no better than with lvl 6 :/ I know I must suck so please any tips would be welcome...

I'm Rt/N lvl 15. Taking Warrior, Healer and Shock hench with me. Should I take some other henches?

Any ideas are welcome. I have only that quest left before I leave for mainland. And if newbie island is this hard I don't want to think about read deal

you can always come back to the island after you go to the mainland. just level up in mainland and come back and try again when u are lvl 20