Tales of the 108 Stars of Destiny
So, there's an ancient Chinese novel called Shui Hu Zhuan, which can be translated as Water Margin, or Outlaws of the Marsh. It tells the tale of 108 banished demons who repent and reclaim themselves from exile. They are reborn as 108 heroes who come together to fight for truth, justice, and the pre-American way. Suikoden is a Japanese translation of Shui Hu Zhuan, and like the novel, it features 108 stars of destiny uniting to combat some greater evil.
The most unique feature of Konami's (Genso)Suikoden series is the large amount of playable characters. You do have to locate 108 stars to join your war party at your castle, and though not every star is playable, most are, so you have some seventy characters to choose from. This negates a lot of character development in all but a few key characters. However,unlike, say, Final Fantasy, every Suikoden game takes place in the same world, and the parts build off each other. So some characters come back. For example, Luc, the arrogant wind mage, appears in the first three segments of the series, but his intentions and purpose differ widely.
The world of Suikoden is controlled by the force of 27 True Runes. Ordinary runes allow the bearer to cast magic and execute nifty combat commands, but the True Runes are much more powerful. In addition to unique spells and other random mystic crap, the True Runes make the bearer ageless. Not everyone is able to weild a True Rune, and the Runes themselves select their bearers, sometimes controlling them. There's a lot of, uh, existential angst connected with the Runes. Nash doesn't have one, but a lot of people associated with him do, and they are an important part of the series, to say the least.
Nash is from Harmonia, the theocratic superpower of the Suikoden world, but there are many nations and governments that make up the fictional geopolitical scene. The creators of the series work hard to show that war can exist without a villain, and so two "good guys" may fight each other simply for the sake of their country. An emphasis is put on military strategy, and there are always important tactical battles that require an entire army. So it's a good thing you recruit one.
Of course, the best way to learn about the series is to play it. Suikoden I was considered the best RPG on the Playstation until Final Fantasy VII was released. The rest of the series has also been released on Sony platforms. It can be a bit tricky to find, but Suikoden V, at least, which just came out, should be readily available. I like the second and thrid installments the best, myself, and you can check them on ebay if you are interested. There are also several spinoffs to the series, including the text-adventurish Suikogaiden and Suikoden Rhapsodia, a tactical RPG.