He shoots this golden ball that spawns a bunch of little flying balls and a single one of those one shot me lmao.
Classic. Also, welcome to modern GGG boss design.
What you are supposed to do is use the statues (that can get animated and move around) as cover, as they block the projectiles. You're not really intended to dodge or tank the projectiles, but it can be done. I think they mostly do elemental damage, so evasion won't help. Capped resists and at least 1500 hp would be good.
How you are supposed to figure out that the statues block the projectiles I have no idea.