I was trying this on hardest difficulty... not very viable. Though Im not very proud of myself i found an asier option: behind that machine (before it lands and after) there is a spot (not the closed door) under a kind of "ladder?" that you can't climb but there is some space and offers a good protection (95% of attacks won't get you). Even on low levels (I had 350 life points) if you ingest a potions you should be able to easily survive the attacks that eventually falls in (very rarely). Meanwile concentrate your attacks on one enemy (I guess it will help if you inflict water purge state before getting in the spot). After defeating one, everything will be very easy.