I think Venat might have been born in a world where the wrong heroes live. To me it seems like Lightning and the others might have been fitting to colaborate with. Technically the XII heroes do not even really work against Venat, just against how Vayne uses this connection but Venat's goal is beyond that and giving fate back in mankind's hand is just right up the XIII guys' alley as long as Venat would not come up with something like "you have to live that out like Vayne would have done it".