First, stop with he multiposting. Put everything in one post.
Since Brawl there have been 3 Fire Emblem games released. Shadow Dragon, New Mystery of the Emblem, and Awakening. The first 2 are Marth's remakes and Awakening is Marth's world. Gaiden takes place on another continent on Marth's world and it is hinted that the Jugdral series takes place 1000 years before Marth's games and that the Tyrfrying is actually the same sword as the Falchion. 6/11(without remakes) or 8/13(with remakes) games take place in Marth's world and the majority of lords are heavily inspired by Marth. Why do you think so many of them have blue hair?
I don't mean "lord" as in the class. Lord usually refers to the main character of a FE title, the ones who aren't allowed to die, in the FE fandom. Ike, Robin, Micaiah, and Sothe to an extent all would be called lords in this sense, while Lucina wouldn't even though she has the lord class because she is allowed to die.