The New Musician of Chaldea (not a story but an idea)

Classification/ No story but how it goes

Like i said in the synopsis, this character belongs to StreamingVikings story "Wearing Grey" on fanfiction.net so give him/her credit and go make sure to give it a read despite it having only 5 chapters it is still good.

Class: Avenger- Demi servant status

Name: Anders (Host and who is in control)

Salieri (Heroic Spirit and "appears and whispers like a devil on his shoulder" basically acts like a ghost that communicates and helps Anders)

Abilities: Standard Master/Servant stuff like Astralizing, can scan servants to check their available stats

Sound Manipulation: he has a perfect memory of every song he has ever heard and can play it perfectly as if he made it himself and he can use his sword as an instrument (EX: He uses his sword and draws it on his arm like a Violin Bow it would produce a violin's sound) and he can produce the sound of an instrument despite only touching empty space.

Sound Resonance: A technique using sound manipulation to draw the linking between two locations such that if a crate was damaged its sound of damage would reflect and produce damage onto the affected object causing possible major damage. (read the fic to get a better explanation and proper detail)

Hellfire: He has the ability to use hellfire in a variety of mid-range combat attacks and possibly coat his blade in it to affect his slashes

Rapier skills: self-explanatory but basically Salieri had a high noble/royal friend, and he learned fencing from him.

Ghost/Spirit control(?) and summoning: with his music he can summon ghost like spirits to aid him in fights by either stalling the enemy or possibly overwhelming them. (Think like Apocrypha's Yggdrimelenia using Homunculus and golems to try and fight the red faction servants as well as owning their own servants, but the spirits aren't really affective except for distractions and stalling when it comes to high level servants)

NP is unknown.

What I would add to abilities

Music Buff/Debuff field: while playing music all allies within the vicinity will receive a buff in stats and strengthen their abilities and reduce mana costs while enemies will weaken and suffer slight mana drain.

Performance of Hell's Musician-NP: (kind of like Elisabeth Bathory's NP that summons her castle with a giant speaker) He would summon giant magical speakers and stereo's at max volume with magic circles that amplify sound attached with a band of Anders/Salieri looking spirits joining behind the real Anders and help do a performance and the song will be amplified by the speakers and the sound will unleash various slashes made of sound and hellfire (while being loud to the enemy causing sound based damage which goes around magical resistance while the enemy could possibly resist hellfire slashes) and cause pillars of fire to appear near the enemies at random in a large field and as the performance climaxes hellfire spreads everywhere in large areas (kind of like Emiya activating his reality marble but then stops at the moment before he fully deploys just giving the large fire affect or Muramasa's NP but without the swords and the creation of his true sword) and then the performance ends. The attack pattern of the slashes and pillars varies based on the song played allowing Anders/Salieri to swap songs played allowing for a variety of attack patterns.