Rumbling Hammer
Rare item - Cursed
Beautifully crafted Greatmaul (1d12 + STR Blugeoning).
(1 / encounter) Turn any attack into a crit (or make a crit explode). The hammer's grip on your mind strenghtens each time.
It starts with a twich on your dominant arm. But then it grows. By the time you realize what's happening, a voice in your head keeps on repeating: "Fight. Slay. Destroy."