I read your comments guys and here are my conclusions :
Indeed he's not another counselor, he's here to fight, to rescue people, not to escape, so:
-Remove entirely his ability to escape, get in cars, run to the police spot...
-Give him a knife
-XP multiplied by the number of counselors alive
It as been said : he's not affraid of Jason, the guy is a psycho (escaped from an asylum if I remember correctly?)
-Remove the composure element, no stumbling, no freaking out, no noises, no nothin!
-Change his lines
Jason tends to ignore nearby characters to chase him instead (part 6 finale):
-Give him the "hey maggothead" ability (a taunt move). Provoked Jason can only sense, hit or grab Tommy (effect lasts 30 sec, one use only)