It's honestly more like a "would be cool"-thing. Still, even though the percentage is very small it could still be a fitting conclusion for season. The idea this:

Vox gets beaten by Charlie and co. while the other Vees do nothing because Vox betrayed them. In a way. Kinda.

Anyway, he gets beaten, but before he can be killed, Velvette "saves" him by making a "triple-deal" with Vox, Heaven and the Hazbin-Crew.  
The deal would be like:

>Heaven, the Hazbin Hotel and all its members and allies, and the Overlords known as The Vees make a truce.

>The Overlords known as the Vees in particular swear to never start a war with Heaven ever again.

>In exchange, Heaven and those belonging to the Hazbin Hotel must swear that they won't kill Vox. Neither directly nor indirectly. Furthermore, the are also not allowed to start a conflict with the Overlords knows as The Vees. Also, all allies of the Vees who have survived so far, must be spared.

>The Overlord named Vox meanwhile will give his soul and powers to the Overlord named Velvette, and has to swear that he will from now on work as an assistant for the Overlords Valentino and Velvette.  
The remaining Sinners who fought alongside with the Vees meanwhile have to swear to serve the Overlords named Velvette and Valentino.

  
This contract would have several benefits because:

>A) Vox gets a fitting ending by getting humiliated for his attitude

>B) Velvette's and Valentino's power as Overlords increases because of all the Sinners who fought with Vox and lost the battle/war.

>C) Velvette's reputation increases

>D) The Vees can expand their influence without fearing any conflict from Heaven's side

>E) It would very likely make Alastor respect and acknowledge Velvette as an Overlord

  
Also, assuming those who claim (though it's mainly on YouTube) that Alastor would be the villain of season 3 are right, it could make things very interesting because it could put the Vees into a neutral faction that won't interfere any further and instead observe things while gathering more and more souls.

In any case, Velvette would just win and become even more powerful while the rest just suffers and struggles.

And Vox would just get the Husk-treatment xD

Theory (though it might very likely never happen): Velvette gets Vox's soul and makes him a Husk 2.0.