Balythas' Staff of Lightning

This staff can be wielded as a magic quarterstaff that grants a +2 bonus to attack made with it, as well as to the user's spell save DC. It also has the following additional properties, when one of these properties is used it can't be used again until the next dawn (long rest):

Pact recovery. You can regain one warlock spell slot as an action while holding the staff. 

Lightning. When you hit with a melee attack using the staff, you can cause the target to take an extra 2d6 lightning damage.

Notes: Bonus: Spell Attacks, Bonus: Spell Save DC, Damage: Lightning, Damage, Control, Debuff, Combat