Help with an artifact (40k Spear of Twilight)

[a humble lich]

The thing with 40k is that it is rarely consistent with itself. Between all the different editions of the table top game (often with differences between the game stats and the fluff), the novels, and the various RPGs (i.e. Dark Heresy, Rogue Trader, etc.) there are so many different versions. The version which I wrote up was based on the description of the OP, the descriptions in the Lexicanum and wikia, and the Diresword in Dark Heresy (as that is the closest they have to a Singing Spear that I know of).