“Heh, these old bones are still good for something. Farewell, my prince. Live, and grow strong…”
—Jagen if he was made the decoy in Prologue IV of Shadow Dragon
Jagen (ジェイガン, translated Jeigan in the Japanese versions) is a playable character in Fire Emblem: Ankoku Ryū to Hikari no Tsurugi, Fire Emblem: Mystery of the Emblem, and Fire Emblem: Shadow Dragon. He is a veteran knight of Altea. He acts as Marth's guardian and often is one of the people Marth turns to for guidance. He is an invaluable unit at the start of the game due to being a much higher level than the rest of your units, but he has terrible growth rates and potential that severely handicap his usefulness later in the game. He steps out off the battlefield in Fire Emblem: Mystery of the Emblem but still stays by Marth's side as an advisor. Afterwards, he dies and his position is given to Cain. In Fire Emblem: Shin Monshō no Nazo ~Hikari to Kage no Eiyū~, he only takes to the field once just to train with the Avatar.
According to the Takayashiki Hideo's Mystery of the Emblem novel adaptation, Jagen is 58 years old. 
|Sword - D|
Lance - B
*Normal Mode only.
|Sword - D|
Lance - D
“Sire... Fight for Altea...”
—Jagen's death quote in Shadow Dragon
The word "Jagen" is also used as a term for characters which use up too much exp at the start of the game (only if you choose to use them) and so hinders the other characters' growths.
Jagens are usually promoted Paladins that you get in the first chapter, and appear to be amazing units due to having much higher stats than your other units. However, due to being promoted, a Jagen will usually gain very little experience for quite some time into the game, with the original Jagen actually being an exception. Originally, Jagens always had terrible growth rates and barely any endgame potential. Recent Fire Emblem games are abandoning this trend, however, with the Jagens in Fire Emblem: Rekka no Ken, Fire Emblem: The Sacred Stones, Fire Emblem: Path of Radiance, Fire Emblem: Radiant Dawn and Fire Emblem: Awakening moving toward being Oifeys and all ending up as decent units that are worthy of using.
There are others who are considered Jagens, but this is the generally agreed upon list.
|Marth - Jagen - Abel - Cain - Gordin - Draug - Shiida - Wrys - Ogma - Barst - Bord - Cord - Castor - Darros - Julian - Lena - Nabarl - Merric - Matthis - Hardin - Wolf - Sedgar - Roshea - Vyland - Wendell - Rickard - Bantu - Caesar - Radd - Roger - Jeorge - Maria - Minerva - Linde - Jake - Midia - Dolph - Macellan - Tomas - Boah - Beck - Astram - Palla - Catria - Arran - Samson - Xane - Est - Tiki - Lorenz - Elice - Gotoh|
|Exclusive to Shadow Dragon|
|Frey - Norne - Athena - Horace - Etzel - Ymir - Nagi|
|Cornelius - Mostyn - Miloah - Malledus - Anna - Aimee - Nyna - Camus - Jiol - Michalis - Gharnef - Medeus - Gazzak - Gomer - Reynard - Bentheon - Merach - Emereus - Bathys - Harmein - Kannival - Mannu - Zharov - Khozen - Volzhin - Heimler - Dejanira - Grigas - Hollstadt - Morzas - Dactyl - Sternlin - Larissa - Xemcel - Anri - Iote - Marlon - Artemis - Cartas - Naga|
|Akaneia - Altea - Gra - Talys - Aurelis - Grust - Khadein - Medon - Doluna - Fane of Raman|
|Falchion - Starlight - Imhullu - Excalibur - Aura - Wing Spear - Gradivus - Mercurius - Parthia - Hauteclere - Aum Staff|
|P: Prologue (Shadow Dragon) - C1: Marth Embarks - C2: The Pirates of Galder - C3: A Brush in the Teeth - C4: Battle in the Lea - C5: Champions of Aurelis - C6: Fire Emblem - C6x: In War's Grip - C7: Lefcandith Gauntlet - C8: Coastal Skirmish - C9: A Wyrm-King's Wrath - C10: Princess Minerva - C11: Knorda Market - C12: The Ageless Palace - C12x: A Traitor's Worth - C13: The Wooden Cavalry - C14: Land of Sorrow - C15: An Oasis of Magic - C16: The Battle for Altea - C17: Star and Savior - C17x: Prisoner of Helena - C18: The Sable Order - C19: Manakete Princess - C20: Camus the Sable - C20x: Men and Monsters - C21: Clash in Medon - C22: A Knight-Filled Sky - C23: Dark Pontifex - C24: The Dragonkin Realm - C24x: A World Apart - C25: Chosen by Fate|
|Divine Dragon - Earth Dragon - Event Recap - Fire Emblem - Galder Pirates - Lightsphere - List of chapters in Fire Emblem: Shadow Dragon - List of characters in Fire Emblem: Ankoku Ryū to Hikari no Tsurugi - List of characters in Fire Emblem: Shadow Dragon - List of Classes in Fire Emblem: Shadow Dragon - List of items in Fire Emblem: Ankoku Ryū to Hikari no Tsurugi - List of items in Fire Emblem: Shadow Dragon - List of Music in Fire Emblem: Shadow Dragon - List of weapons in Fire Emblem: Ankoku Ryū to Hikari no Tsurugi - List of weapons in Fire Emblem: Shadow Dragon - Manakete - Online Shop - Reclassing - Replacement character - Sable Order of Knights - Soothsires - Starsphere - Translations (Ankoku Ryu to Hikari no Tsurugi) - Translations (Shadow Dragon)|
|Marth - Cecil - Rody - Ruke - Arran - Draug - Gordin - Raian - Malliesia - Yubello - Yumina - Ogma - Sirius - Castor - Catria - Palla - Warren - Julian - Matthis - Shiida - Linde - Rickard - Samto - Wendell - Nabarl - Feena - Bantu - Jeorge - Cain - Minerva - Merric - Ellerean - Xane - Tiki - Est - Sheema - Samson - Abel - Astram - Roshea - Midia - Maria - Lena - Nyna - Elice|
|Exclusive to Shin Monshō no Nazo|
|Avatar - Wrys - Athena - Cord - Bord - Barst - Frey - Norne - Caesar - Radd - Roger - Etzel - Dice - Malice - Horace - Jake - Darros - Robert - Belf - Leiden - Beck - Dolph - Macellan - Katarina - Tomas - Frost - Wolf - Sedgar - Vyland - Ymir - Michalis - Nagi|
|Medeus - Gharnef - Hardin - Wolf - Sedgar - Vyland - Gail - Rucke - Rumel - Dahl - Yodel - Nehring - Eibel - Willow - Toras - Lang - Lorenz - Boah - Michalis - Jagen - Gotoh - Eremiya - Kuraine - Legion - Naga - Adrah - Anri - Iote - Artemis - Cartas - Marlon - Miloah|
|Akaneia - Altea - Gra - Talys - Aurelis - Grust - Khadein - Medon - Doluna - Ice Dragon Temple - The Dragon's Table - Marmotord - Fane of Raman|
|Falchion - Starlight - Imhullu - Excalibur - Aura - Gradivus - Mercurius - Parthia - Hauteclere - Wing Spear - Aum Staff|
|P1: Meeting - P2: Young Squires - P3: Training Begins - P4: New Companions - P5: March Duty - P6: Bonds - P7: The Final Test - P8: Assassination of the Hero-King - C1: The Grustian Expedition - C2: Rebellion at Medon - C3: Abducted Princess - C3x: Shadows Behind the Scenes - C4: Joy and Sorrow - C5: Liberation of Grust - C6: The Nest of Vice - C6x: Mercenary Squad - C7: The Scarlet Swordsman - C8: Soulful Bridge - C9: Sanctuary of Sorcery - C10: Two Sorcerers - C10x: The Mask Laughs - C11: Anri's Way - C12: Graveyard of Fire Dragons - C13: Frozen Land - C13x: Within the White Darkness - C14: A Mystery Revealed - C15: Return of the Prince - C16: Regaining the Capitol - C16x: Reunion - C17: Setting Sun of Gra - C18: Battle of the Pass - C19: The Last Decisive Battle - C20: Dark Emperor - C20x: Depths of the Abyss - C21: The Wyvern's Dale - F Part 1/C22: The Dragon's Table* - F Part 2/C23: The Dark Pontifex Lives* - F Part 3/C24: Light and Shadow*
*Counted as individual chapters in Shin Monshō no Nazo.
|Downloadable Episodes (Exclusive to Shin Monshō no Nazo)|
|E1: Wind and Thunder - E2: Assassins - E3: What was done by the sword shall be undone by the sword|
|Darksphere - Divine Dragon - Earth Dragon - Geosphere - Lifesphere - Lightsphere - List of chapters in Fire Emblem: Mystery of the Emblem - List of characters in Fire Emblem: Mystery of the Emblem - List of characters in Fire Emblem: Shin Monshō no Nazo ~Hikari to Kage no Eiyū~ - List of items in Fire Emblem: Mystery of the Emblem - List of items in Fire Emblem: Shin Monshō no Nazo ~Hikari to Kage no Eiyū~ - List of Music in Fire Emblem: Mystery of the Emblem - List of weapons in Fire Emblem: Mystery of the Emblem - List of weapons in Fire Emblem: Shin Monshō no Nazo ~Hikari to Kage no Eiyū~ - Manakete - Raman Thieves - Shield of Seals - Starsphere - Starsphere Shards - Translations (Mystery of the Emblem) - Translations (Shin Monshō no Nazo)|