+5 Henry IVs

So I did something kinda dumb...before knowing all about IVs I started merging Henry and now I’m up to his +5 merge with no idea what I started off with...is it possible to know what his boon/bane are? I was checking his IVs from a regular lv 40 and none of his skills even reach the + so perhaps he’s neutral...but I just want to make sure...

And is there any way to fix him? (Make him +atk or +def?)