Background
Legend states this fiddle was originally won in a musical duel with Asmodeus himself. The fiddle was passed down father to son for generations until one son lost it in a drunken duel with a stranger in a tavern. Since then it has changed owners multiple times, wanting to be owned by the greatest musician in the world. While there are many that look like it, and some claim to own it, there is only one true Golden Fiddle.
Abilities
Asmodeus' Hatred
Like it's creator Asmodeus' Golden Fiddle is highly opposed to the forces of good. As such, all good-aligned creatures must make a DC15 Wisdom saving throw or be plagued with horrifying images. Ability causes the Frightened condition. Condition will end after 1 minute.
Fiendish Ability
Gain 1d4 bonus to spell attacks when Asmodeus' Golden Fiddle is used to cast a Bard Spell.
Band of Demons
Once per day, the bard can summon 1d4 fiends to play in his "band" for 1d10 minutes. Each fiend attacks on its master's initiative and casts either Tasha's Hideous Laughter or Bane at the spell's default level. Spell save DC is based off the summoners spell save DC. Resets after a long rest.
Notes: Bonus: Spell Attacks, Frightened, Bard of any non Good Alignment