Unfortunately (if you recognize my profile pic, you know where I am going with this) I have found no Fire Emblem based mods, besides a 3x crit multiplier.
I think that besides artstyle and narrative differences, the 2 series would be greatly mashed-up. Mostly I wanted skins, but perhaps, I will do things myself, and make skins, or make new classes. I wouldn't make an overhaul, but I like the idea of making some skins resembling, 3 Houses, Tellius, or Awakening characters. Truthfully Sacred Stones would be best to add to DD due to the resemblance of story themes.