Nemesis

Okay, welcome back.   So, Nemesis, the Goddess of Vengeance and "Karmic Retribution."  It seems like Karmic Retribution is at most revenge.  Revenge is instant apparently, it's like crack, it only lasts a moment or two.  Who is the star of Revenge?  Asmodeus.  You're never satisfied with revenge.  

Vengeance is very particular.  With Vengeance one wants their victim to know who is behind their downfall, because the precursor to vengeance is that someone has/had wronged you, or had planned somehow to wrong you in some way shape or form.  Vengeance happens over-time.  

There can be many over-laps in Vengeance and Revenge tactics.  The main difference is that those addicted to the idea of Revenge is that they must hide because they're cowardly in a way because they don't want those who would opt-out for Vengeance instead to know when, what, where and why.