its almost soloable by a 68rng!!! it seems very sensible to shadowbind, just utsus up, shoot acid bolt shadowbind barrage slug/side and shoot shoot, once he hits u twice start getting 2nd utsu up
As a 74 rdm, I can solo these with no trouble. Use gravity to pull and burst Blizzard III and Fire III until low on MP. Sleep II so you can rest up then finish with Blizzard III and Fire III. Have the Guardian follow you down the hall and kite him around till you defeat him.
Black mage? Bind, Blizzard IV, Fire IV, Stun (if need to) Blizzard IV.