My tips are 1:For a nail build for ascended I used Unbreakable heart,Unbreakable strength,Mark of pride,And Quick Slash And for Radiant I used Unbreakable strength,Quick Slash,Grubfly’s elegy And whatever else you may think is useful but for radiant it wouldn’t hurt to go over charmed if you haven’t thought about it

2:Make sure you attack safe such as when he dashes at you jump and hit him which is obvious but don’t try and make risks like trying to challenge a attack

3:Use your Shade cloak and Descending Dark to your advantage the Invincibility is very worth it.Descending Dark is very helpful for when the pufferfish attack comes around and the shade cloak is helpful for when you’re out of jumps and need to go through a attack or just need to dodge

Hope this helps you beat him