Celtic and Germanic deicidal weapons.

The slaying of gods, even those of prime rank and cardinal importance, is a not uncommon motif in mythology, paradoxical as such death may seem at first thought, what with the connotations of immortality of the very concept of divinity. Familiar instances of mythical deicide that may readily spring to mind are the slayings of Cronos in Greek and Balder in Nordic mythology. The Twilight of the Gods was expected to sweep away all the prime Germanic divinities. In Irish myth gods also fall in battle; thus Nuadu, of the Tuatha De Danann, and his consort, the war goddess Macha, meet their fatal end in the war with the Fomors.
http://www.jstor.org/stable/1259546