Fire Emblem: Shin Monshō no Nazo ~Hikari to Kage no Eiyū~ (ファイアーエムブレム新・紋章の謎 ～光と影の英雄～ Faiā Emuburemu Shin Monshō no Nazo ~Hikari to Kage no Eiyū~, informally translated as Fire Emblem: New Mystery of the Emblem ~Heroes of Light and Shadow~, and formally translated as Fire Emblem: New Mystery of the Emblem in Fire Emblem Heroes) is a remake of Fire Emblem: Mystery of the Emblem, developed by Intelligent Systems and published by Nintendo. It is the second Fire Emblem remake for the Nintendo DS. It was released on July 15, 2010 in Japan. The game utilizes the Wi-Fi Connection in a similar manner to Shadow Dragon. This is the only Fire Emblem DS game to not be released overseas.
The game stars Marth, the hero of Fire Emblem: Shadow Dragon and the original Mystery of the Emblem as he fights in a conflict known as the "War of Heroes". He is accompanied by his trusted friend, an Altean knight and hero of the war completely forgotten by history, referred to as the "Hero of Shadow". Players can customize this unit, including their appearance, class and growth rates. New prologue and sidequest chapters heavily feature your custom character and also offer opportunities to recruit previously unobtainable characters. One of the extra features is that you can play a remake of Fire Emblem: Archanea Saga. Every character that only appeared in Fire Emblem: Ankoku Ryū to Hikari no Tsurugi, Fire Emblem Archanea Saga, and/or Fire Emblem: Shadow Dragon returns in this installment.
Every Character, unlike in Shadow Dragon, can be recruited in the same playthrough without having to kill other units. As such, it is possible to have every character recruited and alive on one playthrough.
Each and Every chapter's allowed units limit has been increased by 1 to account for the Player's Character.