The art concept of this character is a blues musician who entered a pact with the patron in exchange for a ghostly muse, bringing them great success with music in exchange for assisting the Patron down the line. Him being brought into the fight is his pact being called on.
Mechanically, his concept is a slow-building ramping support to boost allies and the team, becoming stronger the longer a fight goes on.
Ability 1: Brass Blast
Soul Soloist blasts his trumpet, sending a ringed projectile towards the targeted area. Enemies hit by the projectile or in the landing AoE take damage, are slowed and have their bullet speed decreased.
Ability 2: Summon Muse
The Soul Soloist brings forth their ghostly Muse, binding them to either himself or a targeted ally. The Muse scales with Bullet Speed (and Spirit Damage), firing a shot in tandem with the shots the 'host' makes. In effect, they act as a satellite over the character they're cast on, firing along side their 'host'. The faster you shoot, the faster they shoot. When Summon Muse is cast on an ally, any stacks of 'Build Tempo' are given to the targeted ally.
Ability 3: Build Tempo
A passive. The Soul Soloist slowly builds to a crescendo, leeching Bullet Speed from enemies hit by their bullets or abilities. The more shots that are landed on a target, the less they can fire back--and the quicker he can fire upon them.
Ability 4: March of the Damned
The Soul Soloist discards their gun and focuses on their song, creating a large aura around themselves that increases the movespeed and bullet speed of all allies in the radius. Any enemies caught within the aura have their movespeed and bulletspeed decreased. Soul Soloist cannot fire during this time. At the beginning of the song, the benefits / decrease are minor, as it builds to the climax they increase more and more until they peak before slowly diminishing back as the act concludes.
I won't go into upgrades, as numbers don't actually matter more than concepts, but there's a lot you can do here with upgrades if you want.
