Wondrous Item

Uncommon

This blue bugle horn is lined in enchanted copper that can transform sound into electrical force. You can blow a percussive note from the bugle in place of the verbal component when casting a spell of 1st level or higher that deals thunder damage, such as shatter or thunderwave. When you do, any creature or object affected by the spell also takes an extra 1d6 lightning damage. If the spell's damage would be halved on a successful saving throw, this lightning damage is also halved on a successful one. 
In addition, you can use a bonus action on your first turn of combat to blow an invigorating call from the bugle. Any friendly creature within 30 feet of you (including yourself) that can hear the bugle gains a 5-foot bonus to its speed until the start of your next turn.