Generically-Titled Fire Emblem Quest: Epilogues (spoilers)

Epilogues

Garrus, Hero King (Wyvern Monarch) and Eva, Talkative Crusader (Wyvern Lord)
 -The king and queen of Neir ushered in an era of peace and good relations with Dain that drastically contrasted Garrus' predecessor as king. Eva liked to personally lead and address Neir's military, and both were beloved monarchs.

Yvette, Aging Retainer (Paladin)
 -Even into her late-70s, Yvette continued serving Garrus, though she was happy to correspond with Empress Alexia of Dain once more as well. Garrus didn't have the heart to make her retire, and she even as she passed her prime she never completely lost her edge.

Lambert, Terrified Braggart (Mercenary)
 -Lambert died in chapter 2. Every year, Ellen, Nat, Jay, and Reese would visit the remains of Orsin Village.

Natalie, Quiet Healer (War Cleric) and Biff, Boisterous Horseman (Paladin)
 -Natalie retired to a quiet life as a housewife, vowing to never raise her axe again, though she did give it to her husband, Biff. She didn't really have a particularly booming social life, but such a thing was perfect for her, and the friends she did keep tended to last a lifetime. Biff continued to serve King Garrus as a loyal knight. Where Biff's demeanor once intimidated or offended, he was said now to have been able to lighten the mood of any of his friends or comrades. He and Natalie would have a daughter said to have all of her father's zeal, her parents' off-putting demeanor... And much less of their hearts.

Robert, Loudmouthed Lumberjack (Fighter)
 -Robert died in chapter 29. He is remembered by history for his brave act of self-sacrifice against Canis.

Jay, Stalwart Lumberjack (Fighter)
 -Jay remained a lumberjack in Dagda village. It was a simple life, suited for him. Reese visited often in time off.

Reese, Reformed Rock (General) and Misheil, Fire Dragon (Manakete)
 -Reese stayed a knight of Neir all of his life, becoming the respected figure he never was back in Orsin. Marrying an older woman, as he aged people gave him the weird looks, his significant other taking the years much more slowly than Reese. Misheil outwardly expressed amusement at this, but inwardly it only grew as a reminder of their compared lifespans.

Byron, Personable Paladin (Paladin)
 -Byron continued to serve King Garrus as a loyal knight. His wife, Lyra, only became more famous after the penning of a war epic of a play. With their combined funding, they were able to have Byron's mother sent to Rakche and open a bakery, something she had apparently always dreamed of. Byron's daughter is said to have had grandmother's baking mastery, her father's strength, and her mother's lyre skills.

Mitchell, Reformed Thief (Gardener)
 -Mitchell became a respected member of the botany community over time.

Quidel, Hotheaded Tarvosian (Nomadic Trooper) and Salia, Observant Princess (Archer)
 -After his brother and father fell in an incident involving a Deadlord, Quidel found himself thrust into leadership of the Tarvos. He managed to roll with it quite well regardless, no doubt due to his vast historical and sociopolitical knowledge. Under him, the Garou wound up integrating into Tarvos Valley culture easier than expected. That being said, Salia's level head and open mind undoubtedly helped just as much if not significantly more.

Stefyn, Former Coward (Swordmaster) and Dama, Slightly Beastly (Managarm)
 -Stefyn married Dama, considered by many a symbol of the Garou finally improving their relationship with humans. Despite the normally-accepted reality of not all of a Garou's litter surviving early childhood, Stefyn's insistence would one day manage to do exactly that. And they called him insensitive until he pulled it off...

Cheryl, Pegasus Knight (guess) and Logan, Optimistic Summoner (again)
 -The two remained close friends in a platonic sense, but this didn't stop the rumor mill from churning things out, as the two would visit each other often. Logan wound up dragged along for many of Katina's adventures as she grew older.

Gorman, Coincidental Sellsword (Hero) and Laurina, Previous Pirate (Berserker)
 -Gorman and Laurina remained freelance mercenaries, though the eventually-married couple was primarily hired in Heim.

Katina and Bolse, Magical Twins (Mage and Necromancer)
 -Katina and Bolse grew up fantastically, and spent their early adult years traveling a lot. The older Katina and Bolse attracted more than their fair share of admirers, to which they reacted in rather differing ways.

Mina, Walter, and Simon (Archer, Fighter, and Soldier)
 -ahaha remember when Ellen caused them all to die

Victoria, Disgraced Duchess (Sniper)
 -As an aide to Devon, Victoria was able to return to the world of Noban politics, a better public figure and listener for all her horrible experiences. She would eventually also lend her aid to Duchess Phia of Phile in reining in the grossly corrupt nobility of her region, and eventually even managed to successfully petition to Empress Alexia on restoring Malva to its former status as a region of Noba, winning her former people's hearts once again. It can be said that Queen Eva never once had her executed.

Yancy, Bespectacled Spellslinger (Druid) and Maria, Broken Tactician (Bishop)
 -Maria and Yancy continued to work for Corneria and the magical senate as a couple, and Yancy would eventually succeed his old boss as Mage General, vastly improving Heim's infrastructure and, rather controversially, helping turn the Vautou and True Vautou towards a less illicit legacy. Mercenary populations were displeased, but ultimately the most disgruntled more than made up for the newfound lack of organized crime on the sand dunes. Maria often acted as an ambassador and diplomat.

Miles, Disgraced Son (Sage) and Devon, Kindly Commoner (Bishop)
 -Miles died in chapter 46. He was survived by his wife, Devon, and the child he never got to meet. Devon, to her credit, did not run Fathom into the ground as Duchess.

Bryce, Entire Band (Bard)
 -Bryce continued to be a star for his musical gimmick, finally becoming rich and famous.

Asra, Quietly Troubled (Assassin)
 -Devon invited Asra to stay as her guard in Noba, but she couldn't do it. Ashamed of her actions as Porcus, she wound retreat into the mountains to sort out a lot of literal inner demons.

Anna, Shrewd Businesswoman (Adventurer)
 -Anna wound up serving her time and deciding to follow her family's more traditional means of commerce: legal ones. At least up-front. Behind the scenes, she would build an empire.

Ellen, Our Heroine (Hero class) and Zoe, Pegasus Rider (Falcoknight)
 -For decades, Ellen and her eventual wife, Zoe, served the royal family of Neir loyally. One day, Ellen would vanish into the mountains of Tordo, remembering Anguilla's words when undead began to appear again. Those who traveled with her claimed she wound up forced through the Outrealm Gate in a skirmish along the coast. Zoe never gave up hope that she would see her again, however, and before absurdly long she did, but a lot happened during her absence...

Monica, Not Coldhearted (Falcoknight)
 -While she would watch over Salia for years as her duties demanded, a personal chord struck with her upon learning Ellen had vanished as she did, and she almost immediately went to seek her out.