Thunderstruck

Your exposure to storms and elemental magics has left you changed, able to issue a thunderous boom with your voice. Maybe you should join a band? 

You have the cantrip Thunderclap always prepared. You also have the spells Thunderwave  and Shatter always prepared. You may cast these spells once per long rest without expending a spell slot. Once you cast a leveled spell in this way, you can’t cast the spell in this way again until you finish a Long Rest. You can also cast these spells using spell slots you have of the appropriate level and spellcasting modifier.