The Berserk Staff (バサークの杖 Basāku no tsue) is a recurring long-range Staff in the Fire Emblem Series. When cast, this staff will cause a selected enemy unit to be induced with the Berserk condition, whereupon they will engage all units within range, be they friend or foe. Such a detestable effect is, fortunately enough, offset by the staff's perpetual lack of accuracy.
On one hand, the Berserk Staff is arguably one of the more frustrating staves to appear within the series, owing to the fact that it grants enemies the potential to cause the units in one's army to turncoat and attack their allies. As the afflicted unit can neither be rescued nor passed from one ally unit to another, a successful casting of the staff's effects is tantamount to him/her either winding up inflicting copious amounts of damage onto his/her allies or recklessly rushing headlong into a sea of enemies.
On the other hand, however, this staff has the potential to be one of the best staves in the game, especially if it falls into the hands of the player's army. The staff may be used to induce the Berserk status on a fairly powerful enemy unit, whereupon he/she will be able to put a significant dent onto the HP of his/her fellow allies before the player's army reaches them.
The Restore Staff may be employed to counter the effects of this nefarious staff.