From the introduction:
Heroes and Villains: Volume One, offers a total of ten heroic and villainous characters useable (sic) in virtually any campaign setting. They are designed to be useable as ready-made player characters, on the fly villainous opponents, or simply NPCs heroes used to move the plot along.
New players or experienced players just wanting to jump into the action without going through the process of constructing their own character can use these characters in any standard PL 10 (150) campaign. None of the characters presented use skills, feat, or powers from any other source then M&M 2e.
Gamemasters will find these characters especially useful as quick villains and NPCs that can be used without the need of even creating descriptions or histories. The histories given for the NPCs are specifically made to reflect the open-ended "Seven Cities" campaign setting mentioned throughout this book.