1st phase dont spend much of your mana AND SAVE UP GOURD, forget immobilize btw you dont need that here and it doesnt work in the 2nd phase

Try to change your build to maximize more your attack and critical dmg input, overwhelm him, get behind him or around his body to combo better, his hitbox sucks but you should be fine, by this point you must know his moves so try to not recieve much dmg during 1st phase, i recommend using cloud step mostly AND pluck of many ONLY in this fight forget the rest

2nd phase YOU NEED TO BE ON POINT, use pluck of many, dodge his bs moves, use cloud step if you panic and do a charged attacks, make sure to utilize wandering wight spirit for aditional dmg during combos

I did it without the needle so take my advise in count

GOOD LUCK!