I thought the same thing in one piece of the promo art, but it's completely gone in other versions of the art where the characters are closer together. The thin, "wand"-like thing appearing to come out from near V's waist was not part of his character model, but just an outstanding piece of metal in the background or something.
Unless the differences in art just managed to crop out the wand, or...is it still there and I'm just blind in my sick-addled, low-sleep mind...?
Either way, that second promo art gives us a much better look at V's design (tattoos, looks like a dagger or scabbard on his left hip).
I think they deliberately removed it. It's definetly not some random piece of metal though.
It would also not be cropped out completely when looking at the art. Maybe it was something we weren't supposed to see yet.