Thunderclub

This Greatclub +1 has 7 charges. Striking
the ground in front of you, you can use your
action to cast Thunderwave (DC15) and expend
1 to 7 charges. For each charge you expend
beyond 1,the level of the spell increases by 1.
You can use this power even if you are can't cast
spells. The wand regains 1d6 + 1 expended
charges each day at dawn. If you expend the last
charge, roll a d20. On a 1, the club crumbles
into ash and is destroyed.