This ancient looking horn has obviously seen a good deal of action, covered in scuffs and cracks. When blown however, it sounds just as if it were new. The sound that blasts forth from this instrument seems to invigorate nearby allies and encourage them to fight just a bit harder.
As an Action, blow on the horn. You may do this once per long rest. When you blow on the horn, each ally within 60' gains 2d4+4 temporary health.