Staff Expertise Heroic
You gain a +1 feat bonus to the attack rolls of implement powers and weapon powers that you use with a staff. This bonus increases to +2 at 11th level and +3 at 21st level.
In addition, when you make a ranged or an area attack with a staff as an implement, you don't provoke opportunity attacks for doing so.
When you make a melee weapon attack with a staff, the weapon's reach for that attack increases by 1.
武僧的威能都不带weapon关键字……另外即使原文说use weapon也不行,因为武僧的法器威能不考虑武器本身特性,你加的只是weapon reach,不是touch reach……