Originally posted by norrinradd43
I think that whole Havok vs Vulcan thing is PIS anyway because hasn't it always been that Mutant powers have no effect on siblings...Havok and Scott have never been able to hurt eachother directly with their powers...same with Black Tom and Banshee...Unless there is a retcon I am not aware of.
As far as the Summers are concerned, the immunity rule only applies to Scott and Alex.