Voul

A perky, free-spirited riot of a young demon. Hates to be stigmatized as the 'rebellious teenager' cliché but is undoubtedly labeled so by most of his fellow demons.
Voul rarely has anything to do with the actual business his Lord and Savior the Devil entrusts his subordinates with and really couldn't care less about the usual make-deals-collect-souls line. There are countless numbers of demons in hell so why the f*ck does he out of all people have to do the same damn boring job everybody else does? There's enough soul trafficking already so he takes the liberty of ditching that job.
Rather he indulges in the rock band he leads on the surface (the human world).
Voul was always enormously invested in the world above and sought to walk among the humans, not out of love for those stupid two-leggers (how he likes to call them) but out of mischief - the thought of deceiving and dominating humans through manipulation and lies gets him giddy with (sadistic) excitement. (Why tf he doesn't do his actual job then is complete nonsense but don't question his logic)
Thanks to the strange acceptance humans harbor towards odd-looking people in the social scene he moves within Voul was able to build his band on a scary, sort of demonic image and can appear freely in the surface world without any sort of disguise. 
His band is quite popular these days. Loves to (quite literally) screw with humans, prefereably female groupies. Downright basks and soaks in the adoration and screams of his fans.
Still looking for a lead singer since (as hard it is to admit for him) his vocals aren't on par with his electric bass skills. Spends more time writing new songs than committing demon-typical malevolence.
Gets a kick out of mindfucking humans though.

Hosts a giant Halloween concert party every year on October 31st. A very sought-after event and possibly Voul's favorite day of the year.

✽ UNIVERSE RELATIONSHIPS ✽

Khola
Voul is all over him every second of every ever so small amount of time he gets to spend around Khola. Couldn't care less about his secluded but compelling attitude or pretty face, what Voul cares about is his voice. Only once has he, through a blessed coincidence, heard Khola sing and it was a love-on-first-listen sort of deal - Voul wants him as his lead singer and only him, there is not one who could possibly be better fit for the position in Voul's mind.
Pesters Khola constantly about this matter, presses it so much every normal demon would have broken his nose in annoyance already. So far Voul only sees his voice in Khola.

Atil
It is fair to say that Voul resents him just as much as Atil does. Their relationship is based on mutual feelings of antipathy. Since Voul's mind really does not make a difference when it comes to who disrespects his life choices or talks him down it's no surprise he came to dislike Atil the instant they met, after all all Atil did was preach on about him slacking off, having his head in the clouds and being a disgrace to the name demon, after which he continued listing the things Voul should actually be doing rather than play pretend rockstar on the surface.
There's an unhalted expression of disgust on his face whenever Atil is mentioned.
Grumbles and mumbles all the awful things he'd do to Atil if he just could to himself whenever he's been upset by him like a fuming railway.