Nerveshatter is a warhammer associated with the Bosmer Lady Syl, Duchess of Dementia. It is made from madness ore and jagged shards of amber, and is enchanted to deal shock damage to those it strikes.
When threatened, the eternally paranoid Lady Syl would retreat to the ruined tunnels of Xirethard that run beneath New Sheoth and would equip herself with Dark Seducer armor and Nerveshatter. She claimed to have defeated many while wielding the hammer. Syl was killed by the Champion of Cyrodiil during the Greymarch of 3E 433, although it is unknown if she defected to the Forces of Order or if her death was part of the Ritual of Accession. In any case, Nerveshatter was claimed by the Champion.
Nerveshatter later found its way to a Bosmer named Gadnor who won the hammer from a coin toss. Overtime he became deeply infatuated with it, and researched into its origin, discovering that that it was made out of both madness ore and amber. Shortly before his passing, he journeyed to his final resting place in Crystaldrift Cave near Riften, and hid Nerveshatter within the cave with a powerful illusion spell. Only those who had walked the Shivering Isles and brought forth to the hammer's altar both madness ore and amber would be able to claim it. In 4E 201, a manic mage named Thoron used the Sword of Jyggalag in a ritual within Solitude's sewers, to magically cut a rift into the Shivering Isles, resulting in a root tunnel forming in the sewers, as well as flora, fauna, and objects crossing over into Tamriel The ritual was stopped by the Last Dragonborn, who killed Thoron and removed the Sword from the heart of the burgeoning Root system. Some of the Isle's strange objects that crossed over remained however, and would even make it into the inventory sold by some of Tamriel's Merchants. Among them were amber and madness ore, giving the Last Dragonborn the opportunity to claim Nerveshatter, which they did after hearing of an exotic treasure and its rumored location of Crystaldrift Cave.