something is slightly off maybe. but the more MC the longger firewall stays up awell and it all determines when you cast aswell
sometimes my Fw can do no damage to mobs, sometime 1dmg .. or 5, or 40... and once its cast, it seems thats the only dmg that will be caused until another firewall... i dont know if this is what it was suppose to be, but it sure does go out quicker than we may be used to due to other servers having higher MC items and such