This legendary Zither is a long instrument made by a pair of twin legendary swords smiths and monks. Played it summons the embodiments of the fallen soldiers killed by the monks during a long standing war. 
When playing this instrument you have 3 Charges to summon the souls of the soldiers to slice through any opponent in a 80 ft cone DC 15 Dex Save on a failed save take 10d6 slashing damage, and half on a successful one. Hiding behind cover also saves you from this attack. 

Notes: Damage: Slashing