You have resistance to lightning damage while you hold this staff.

The staff has 3 charges. While holding it, you can use an action to expend 1 its charges to cast spirit guardians (save DC 15), which deals lightning damage instead of its normal damage type. When the spell ends, every creature, excluding creatures unaffected by the spell within 15 feet of you must succeed on a DC 15 Strength saving throw or be knocked back 10 feet and fall prone.

The staff regains 1d2 + 1 expended charges daily at dawn.

You can use an action to break the staff over your knee or against a solid surface. The staff is destroyed and lightning burst out in an explosion that expands to fill a 30-foot-radius sphere centered on it. Every creature in the area must make a DC 16 Strength saving throw, or be knocked back 10 feet, be paralyzed until the end of your next turn, and take 11d6 lightning damage on a failed saving throw or half as much damage on a successful save and isn't paralyzed. 

Notes: Resistance: Lightning, Paralyzed, Damage, Control, Combat, Warding