Vessel of Kulemac FInal form

so the final form has very fast spawning orbs that leave the aoe that prevents any healing and drains all the life, i can remove them by making the vessel performa a jump (outranging it or using a portal) but then i cant deal any damage, i am a melee btw, so i was not able to kill the vesel (mostly duo to a bug being stuck inside the middle and cant attack anything) and was woundering, what exatly am i supposed to do to that thing? like i know my damage is mid compared to most of you, i think a good 200k per magma spray, so yea , what or how am i supposed to kill the final form with these orbs constantly destroying me? and no the answer more damge is not the way this time

so noone knows how to beat that boss as a real melee?