I don't have a clue on this one. I'm familiar with the sig of Nick Cave and I think it looks good but not sure. I don't know the other ones: Warren Ellis, Martyn P. Casey, Barry Adamson, Conway Savage, and George Vjestic.
I'm always a bit sceptical about these multi-signed pieces: the same pen, largely the same style, quite easy to forge I think.
Any opinions are appreciated!