Invisible Wand of Invisibility

An invisible magic wand. Expend 1 charge to cast Invisibility or boost a spell, +1 to attack and +1 damage. It holds up to 6 charges, regaining 1d4 charges at dawn.
If it is reduced to 0 charges, roll 1d20. On a 1, the wand is destroyed (invisible fireball, centered on self). Creatures failing their save are invisible to themselves and each other for 6 minutes. The creature holding the wand automatically fails its save, and a creature targeted by the wand, if it is in the blast, has disadvantage on the