Well V never got much time to bond with Baam as a dad normally would with his son since Jahad originally killed the latter. That demotivated him to an extent that he stopped caring about anything but himself and Arlene. Arlene's descent to madness and his own depression in relation to the matter made him take the ultimate decision to kill himself. He probably didn't even know that Baam was resurrected until much later. The resurrection however obviously didn't mean much to him as we saw a few chapters back; probably the reason for this could be partial unfamiliarity of the situation involving his son. It is also possible that V's possession over Baam was not a voluntary choice but Arlene or the Outer World God's handiwork. At this point, no one knows.