mappo physical resist question

[Game]

I tried shaa sword, 2x bk rings, and amp from saracen ammy and still couldn't put a dent in him. What part of Last Wish helps?

Edit: tested again, i do just enough damage with IK set, shaa sword, saracen ammy, 2x BK rings to make his health go down a hair and bounce right back up to full

Last Wish has -30 physical resists, ssshaa sword effectiveness is only 1/5th if they are immune to the element, so Last Wish provides MUCH more piercing.

[LordManhammer]

Last Wish has -30 physical resists, ssshaa sword effectiveness is only 1/5th if they are immune to the element, so Last Wish provides MUCH more piercing.

Is the version of Last Wish in our wiki not up to date? I don't see -phys res on it.