Nell is a character from The Legend of Zelda: Breath of the Wild. He is a Hylian encountered by Link at the Akkala Bridge Ruins in the Akkala Highlands region. Link encounters Nell fighting a Moblin on the broken bridge leading to the Akkala Citadel Ruins.
Link can assist him by defeating the Moblin and Nell will reward with a random item. Then if Link talks to Nell, he reveals that he came to Akkala to visit the Akkala Citadel Ruins. He explains that during the Great Calamity after the fall of Hyrule Castle, the remaining Knights of Hyrule and Hyrulean Soldiers fell back to the Akkala Citadel where they made their valiant last stand against Calamity Ganon's force of monsters and Guardians. One of the soldiers was Nell's ancestor. He had come to pay homage to him, but was unable to reach the citadel due to the broken bridge and the patrolling Guardians.