This quest is easily duoable. I went as a 75RDM/NIN and my buddy went as a 75NIN/DNC. First clear out the wandering imp's, buff up and click the ???. Run up to the gate and commence. I casted gravity on the Lamia No. 27, while the my partner strait tanked the qutrub. Kite the lamia back and forth down the path while the NIN kills Moshdahn. As I was kiting the Lamia I was easily able to haste/regan the NIN, and cast a few enfeebles on Moshdahn as well... After the Qutrub is dead the NIN then tanks the Lamia. -Easy 30k made off gold coins- Make sure to keep NIN hasted and keep shadows and stoneskin up cause the Lamia can cast some nasty spells. All in all went pretty smooth..
Midgardsormr
Fizgrim
75RDM
67BLU
55BLM
40NIN
" I " Make it rain..!!