Farm health beforehand, with the other bosses just mend when theres knly an npc left or the boss is weak, for the malixe kitsunes i prefer to just drain them.
Oh yeah ylu have to farm the drsin ratio, you csn either spend some hours draining, over 200 should be more thsn plently but if youre lazy you can go shift ctrl i do some bs magic and activate debug mode then just put the number you want
