It's most likely impossible because you don't have a shield for some reason.
I have buckler
Oh sorry, I didn't see that.
Something that would give a minor improvement would be for the ruby to hit both the shiv and the spear.
But, I have a belt of Knives and it would be a waste if I separate the two.
Always died at around 350 hp for the boss
gonna give up on tryna beat it with this setup
Also, the brutal spear has a golden whetstone on it and +2 poison from the forge.