Difficult in the cloth quest

I've looked around the forum but did not find answer to my question so I decided to post to see if you help me. I am in quest of the first secondary armor bronze climbing a staircase, as she climbed several times after some faced a boss and continued to rise which arrived at MU, I died several times before I could beat him, but the staircase continues and when I got in other head like Cassius I died. I was wondering if this quest is so hard anyway because she asks cosmo 6500 and I already have 10,000.

I appreciate the help :)

After meet Mu i kill ALL and then get out to claim the price (i just kill them all, and when i get out i can delivery the quest)