This is the forum for helping you out if you're stuck or if you want to discuss the nitty gritty details of the dungeons within Mount Grimrock. Warning: forum contains spoilers!
I was wondering if someone could give me a little advice on the Cube O'Death. I got the so-called "Weapon of Power" and that does pause the cube, but no matter what I hit it with: swords, bombs, magic, the weapon of power, it seems to do zero damage. I've tried to stop him on the center of the device, but that didn't seem to have any effect. Maybe it is my sleep-deprived brain missing something obvious, but I would appreciate a little help. I'm tired of getting squished.
You have to stun him with the weapon. While he's stunned you can take out the parts you added (if he lies on the right side ). After you took all 4 parts he is immun to the stun but gets damage. I would use range weapons, bombs and spells because he will crush you in melee range.
2x2 is not advised with him as he moves super fast. Your best bet is electricity. There's an electric wand in one of the three rooms. Mob randomly drop keys for the locked three doors.