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

The staff has 10 charges. While holding it, you can use an action to expend 1 or more of its charges to cast one of the following spells from it, using your spell save DC: crusader's mantle (3 charges), dawn (5 charges), or guiding bolt (1 charge).
As an action, you can expend 10 charges to force every creature within 30 feet of you to make Dexterity saving throw against your spell save DC. A creature takes 12d12 radiant damage on a failed save and half as much on a successful one. Once you use the staff in this way, you can't do so again. 

The staff regains 1d6 + 4 expended charges daily at dawn. If you expend the last charge, roll a d20. On a 1, the staff flashes, and disappears in a burst of light.

Notes: Resistance: Radiant, Sorcerer, Warlock, or Wizard, Damage, Control, Combat