Probably One of Gorosei & He will collide with Thousand Sunny
I think it will serve to both Stop him from ruining Vega's Message & also to force Brook to Attack him
It's possible that Brook can Hurt Gorosei
His Soul draws Energy from Hell/Afterlife
Which i think is related to why Gorosei can't be Damaged nor seem to feel Pain
It's like They are already Dead & this is just Projection (Similar to Perona's Powers, but on Steroids)