The Nemesis system is one of the most-intriguing game mechanics of the past decade or so, as it allowed you to build a connection with random enemies and technically make any average Joe a rival worthy of being called your nemesis.
While that system has been patented and locked away by Warner Bros. it hasn't stopped other developers from being inspired by the idea. Specifically, Ken Levine's Judas looks to take the Nemesis system's ideas up a notch through what he calls the Villainy system.
Essentially, in Judas you're going to have to pick between the Big 3, which are factions that are in charge of most of the game world. They'll look to charm you, bribe you, and you'll see members of the factions around the map.
If you ignore one or when you eventually decide to join one of the Big 3, the others will take notice and the characters they send will become your villains. They'll get access to new powers to subvert your actions and goals, and we're promised a lot of character-specific interactions depending on your choices in Judas.
The system certainly looks interesting and differs from the Nemesis system in a lot of ways even if it takes inspiration from it. We'll have to see how it plays out when Judas launches, which is some time in the future.