The cunning NPC and his reincarnated villainess

Once a reincarnation or two show up in the world of a game, they tend to mess up the whole story - but then what if a ripple that their appearance created caused a seemingly random NPC to move forward on his own?
The haggling demon.
Cunning, ambitious, ruthless, always on the grind.
The male yandere.
While the reincarnated villainess and the reincarnated heroine try to change the world in their ways, the world starts revolving around him instead!
All hail the rise of a new crimelord!