killing the unkillable before, he defeated and killed a completly diffrent character..great...
he could just shield himself and that blast would do nothing...if its magical, it would fly back and knock NT to his feet
also the KMC rules clearly state, that beings would have the effects they would have if they were part of their own world...like for example speed force for DC characters, so Kain woudl have his unkillable nature completly in its raw form....not even soul stealing will defeat him