Nash is a young boy with short brown hair and purple eyes. He has small freckles across his nose. He wears a moss green vest over a light purple, long-sleeved shirt and grey pants. He also wears brown shoes with light brown socks.
Nash is a stoic and calm child, but possesses a rather bratty nature towards Asta, often being more critical of Asta due to his inability to use magic and his failure to have Sister Lily accept his marriage proposals.
Aside from his initial behavior, Nash shows that he truly does care for those close to him and would do anything to protect them if danger arises their way. This can be shown when he tries to protect Sister Lily from an attacking elf, showing that Nash can be brave if it means protecting his loved ones.
One day, Nash teases Asta after Yuno interrupts Asta's series of proposals to Sister Lily. While lighting a fire to help Recca boil a pot of water, Nash reminds Asta of the differences between him and Yuno. The following March, many of the villagers gather to watch the Grimoire Acceptance Ceremony. Nash and the others from the orphanage are shocked when Asta does not receive one but Yuno receives a four-leaf clover. They then head back to the church for a feast.
Six months later, Yuno and Asta entrust Nash with defending the church when they leave for the Magic Knights Entrance Exam. A few days afterward, Asta and Yuno each sent a letter back to the church and Nash was surprised to learn that Asta had passed the exam.
Several months later, the villagers of Hage are left confused after the kingdom is saved from the Arrows of Judgment and the demon skeleton shines with light. They watch as a dungeon rises over the skeleton and passes overhead. A possessed Purple Orca then attacks the villagers. When the elf attacks Lily, Nash jumps in front of her, and the pair are saved by the arrival of Yuno and Asta.
A few days later, Nash reads the newspaper article about Asta's trial.
- Fire Magic: Nash uses this magic attribute to generate and manipulate fire. Without a grimoire and with limited mana, he can only manage to create fairly small fireballs.
- Enhanced Strength: Nash has a high level of strength for a boy his age. He does 300 push-ups without showing any signs of exhaustion afterwards.
Initially, Nash found Asta to be childish and annoying. Nash would often criticize Asta, and when Nash finds out that Asta is aspiring to become a Magic Knight and eventually the Magic Emperor, he continues to discourage Asta even more. However, Nash took Asta's ideology to heart: it does not matter where you come from or if you are rich or poor, anyone can achieve their dreams of greatness. When Asta left for the Magic Knights Entrance Exam, Nash promised that if Asta passed, he would start to believe in Asta's ideology.
Despite his initial attitude toward Asta, it is noted he truly does care for Asta when he hugs him and says his goodbyes to Asta and Yuno. Nash has since then been happy for Asta after he manages to become a Magic Knight.
After finding out that Asta passed the Entrance Exam and hearing about Asta's successful career as a Magic Knight, Nash began to admire and idolize Asta, though for the sake of his pride, he makes an effort to hide his admiration.
Nash now dreams of being just like Asta and tries to imitate him. Nash has been doing Asta's workout regiment and has been acting more like Asta.
Like all the other orphans in his village, Nash has displayed praise towards Yuno because of his talent in magic and accepts Yuno as far more capable of being a Magic Knight than Asta and seems to hold more encouragement for Yuno.
- Nash ranked #46 (tied with others) in the first popularity poll.