Edge of Eternity
From Warhammer 40k - Lexicanum
The Edge of Eternity is an ancient Necron warscythe and is a relic of the Mephrit Dynasty[1a]. By custom, it is only carried by the master of the Cryptus System and is currently wielded by the Overlord Zarathusa[1b]. The Edge of Eternity is a deadly weapon that employs complex phase technology, so its blade can literally ghost in and out of existence. This allows the warscythe to bypass almost all kinds of armour and reappear deep within its wielder's foes.[1a]