Lol I thought you said that marth is the only character in fe that ever made it to a smash game my bad smash definitely need s more fe though ike is my favorite character in brawl (and the only one I got around to using in general XP)
She's been an assist trophy since Brawl. All she does is stand for a few seconds and then slashes an opponent in a split second. She can't be playable due to not being the main protagonist is FE7 (that title belongs to Eliwood, who is impractical to be made playable due to being a horseback rider). So far, Marth is the only FE character playable.