Bishop was not really good with both melee or range weapons. He is lucky with marquees sense he is living but with normal weapons he sucked at them very much.  Regina and a few higher ups decided to try something, this Intel was for high level clearance only, so they created a staff that looked like a sheperhds crook. Within this staff it has a gem within the middle of it, despite its appearance this gem plus it's corresponding half in bishop are a magic type source, sadly this can cause corruption within  bishop 5-AI segment which can cause him to have amnesia, disorientation, highnented emotional states(like a pregnant women with mood swings but 100 times worse), and impaired motor control alternatively.  If bishop were to release a sudden dynamic burst it would be serverly draining to bishop energy to the point it will force him to shut down permanently.

It is why Regina tries to keep this info on the down low, so far only bishop, rook, pawn and king knows of this. Though anyone else outside of these five do not know of bishop hidden ability, it is unknown where these two gems came from but despite how many times she has been told to remove the one in bishop. Regina had declined the higher ups advice every time because she knew taking it out would do more damage then leaving it in, as the other gem had already attached itself to bishop fully becoming one with him. The gem is located within his chassis.  Sense bishop knows the risk of using this ability he tries not to use it much but he is also mindful of the gem within the staff so it doesn't break.  The other half of the gem is still part of bishop when in his myth form but it is located hanging around his neck instead, while in his alt mode it is well hidden.

Bishop looks:

Blitz_Dragon