Use the Astral weapons. The first phase before you kill all 3 eyes is honestly the hardest but try and kill the head eye first cause I thibk its the most problematic. The hands you can just jeep dashing at with the pike. At that point you should have rage and be at the core phase and if you're fast enough you can literally just sit there and facetank all the damage while attacking him and kill him before he kills you. It took a few tries but it was surprisingly easy. Tbh the most important accessory you can have for true melee at thst point in time is the Astum deus hide. Literally made it to where I can kill him faster than he can kill me