Background Information

Violinist of Hameln is a completed shonen manga series with 37 volumes created by Michiaki Watanabe.

It's premise is that a group of adventurers are traveling north to the Northern Capital (a.k.a Hameln) to prevent a catastrophe. In this world, music has magical qualities. The actual story revolves around the hero Hamel who travels northbound towards the continent of demons in order to avert a great disaster, at first the manga has a less-serious tone, basically being as simple as Hamel using his magical oversized violin and playing music that forces his enemies to repent for their sins and kill themselves. Later on, however, the plot thickens and we find that Hamel is a Mazoku and that the reason he's heading northbound (Hamel and his six strong team: Oboe, Flute, Raiel, Trombone, Sizer and Ocarina) is to prevent the resurrection of his father Chestra the Demon King.

A sequel to the series called Violinist of Hameln: Shchelkunchik is also completed with 8 volumes.

It involves the travels of a young boy named Schel who wishes to become a wizard. Along the way he meets Hamel's son Great.

Standing in the Battledome

The verse has a plethora of at least multi city block/town/city level characters and a 100% Chestra is easily a planetary threat, they only seem to suffer in the speed department.

There also a few characters that can compete with the high tiers from the HST, but characters like Mazoku Hamel or Chestra are able to fight easily against the S-Class Demons from Yu Yu Hakusho.