Divine Sparks are supposed to be unbreakable. But there are two people who can break, shatter, eat, absorb, digest, or forge them: Bebe, and Beirut. Beirut has created many over the countless years while Bebe's first Godspark weapon was a longstaff, created in order to hide Linley's two Overgod Talisman within it.
To create one, both Bebe and Beirut have to eat a lot of Divine Sparks (generally Highgod Sparks), during dozen of years, and forge a weapon. Beirut often eats Divine Sparks according to the affinities of his customer. Indeed, for Bebe, he has only eaten Darkness-Type Highgod Divine Sparks. For Linley, Beirut has eaten Fire-Water-Earth-Wind-Type Highgod Divine Sparks to create Mirage, as it would yield a better result.
These weapons are extremely rare, and are way better than Highgod Artifacts. Their toughness is comparable Sovereign Artifacts.