So, I hit 25 and I finally got a chance to fiddle with the Nemesis system, and its pretty sweet. Originally I thought you only had to design a character, but after trying it out, it turned out to be a lot more deeper.
You have to pick what kind of minions you want... About 10 or so options, everything from, undead to ninjas to robots and even a few varied types of demons or aliens.
Then you pick what sort of powerset the minions fight with. Followed by, what kind of crimimal is your Nemesis (Mastermind, Maniac and Savage)?
What powers they use... And finally you get to create their look.
The first quest I had for my Mastermind type was to stop a robbery at the museum... It was pretty interesting to watch the dialogue between the characters, and a blast to watch my Nemesis waltz in like she owned the place.