So I got an acid vortex on sight. Several tiles away so I thought no problem. Started shooting it with blessed eternium arrows (good longbow, 7-8 bow skill, nice slaying ring on finger) but it barely took any damage. It exploded. Only thing it destroyed was 5 out of 6 blessed corruption removal scrolls Khelliemeister gave me.

Probably just a bad roll there but is there any way to protect the inventory from acid damage? I was acid immune myself so that obviously did not help.