Sorry, but this needs some updating. Not including trophies or assists here because no one has time for them.
Four Times Tier
FE1/FE11 (Marth Melee, Brawl, 3DS, WiiU)
Two Times Tier
FE10 (RD Ike 3DS/WiiU)
FE13 (Robin/Lucina 3DS/WiiU)
FE7 (Roy appears in the epilogue of this game so I'm counting it)
FE9 (PoR Ike Brawl)
If we're talking about non-playable characters in Smash, there's a bunch of trophies from many of the games, the FE2 attack theme remix on the coliseum stage, Lyn assist, Arena Ferox . . .