you can't give a severe phobia to the matrix with psychotropic. 15 BP max, which means if you want a common trigger, it has to be moderate at most.
now, the matrix is pretty pervasive in SR4. you can't really avoid it. frankly, if there was a category even more common than common, the matrix should probably be in it. point being, the matrix is not something that imo you can validly claim to be an unccommon trigger for a phobia. it's everywhere in some form or another.
you could arguably give a severe phobia of your PAN, i suppose (or the node the bomb is set up in, etc). which would get similar results, i suppose.
now, the matrix is pretty pervasive in SR4. you can't really avoid it. frankly, if there was a category even more common than common, the matrix should probably be in it. point being, the matrix is not something that imo you can validly claim to be an unccommon trigger for a phobia. it's everywhere in some form or another.
you could arguably give a severe phobia of your PAN, i suppose (or the node the bomb is set up in, etc). which would get similar results, i suppose.
Indeed, Moderate (They both are at -4, whcih is what I was remembering, but Sever adds an additional Composure (3) test to the mix)
However, Moderate or Severe, it is a trigger that will keep them incapacitated for a bit. But yes, if you want to really screw them, make it a Sever FOR THAT SYSTEM... Problem Solved...