Well, more or less. Most of the Devil Summoner series have the Devil Summoners as protagonist, or at least important characters to the plot itself. (Don't know about the Shin Megami Tensei III: Nocture Special Edition though... Haven't play that one)
There are two cases of Devil Summoners itself, though. One, Devil Summoner which fights to protect the people. Two, Dark Summoners, for profit and self-serving purposes. (Take from wiki for Dark Summoners)
...Wait, greatest Devil Summoner...
...Will Sakura be almost as badass as Raidou himself O_O!?