His Blade is the Ouroboros Knuckles. His class is Martial Artist (Attacker). He has a straightforward, caring, and compassionate personality. On the other hand, he has a side that likes to act cool. While he is said to be relatively dense, he quickly grasps situations at key moments, so he isn't incapable of reading the room. His Talent Art is "Gigantic Beat" (recharges all Arts on hit). His standard Arts are Backspin Knuckle (Single-target physical; Break), Mighty Strike (Single-target physical; increased damage when hitting from the front), and Revolt Upper (Single-target physical; Evasion, increased damage on cancel). The power of Ouroboros is built into his Ouroboros Knuckles.

Often travels with Matthew. Has an androgynous appearance and uses the first-person pronoun "Boku" (soft/polite). Possesses a personality that judges things calmly; while expressionless and prone to mechanical speech, A is actually caring and kind-hearted. The Blade is a Monad (a slender Monado; the blade glows bluish-white when drawn). The class is Monad Fencer (a Healer capable of a certain amount of offense). Talent Arts include Vision (nullifies attacks against the party for a set time, with usage limits) and Vanishing End (an Ether attack against all enemies that ignores defense, usable when using Light Field during Vision). Standard Arts are Cross Ray (Single-target Ether; heals nearby allies on hit), Shaker Edge (Single-target Ether; Topple), and Light Field (sets a Regeneration field around self).

His class is Machinist (Defender). His Blade is the Variable Backpack (self-made mechanical arms). He is gentle and quiet but becomes talkative when it comes to machinery. He hits it off well with Shulk, a fellow mechanical enthusiast. His Talent Art is Total Destruction (Area Ether attack around self; ignores defense, reduces damage taken during use). Standard Arts are Whirlwind (Area physical attack around self; increases Aggro gain), Strong Assault (Single-target physical; reduces damage taken during use), and Motor Razor (Single-target physical; Launch).

Her class is Cantor. Her weapon is the Great-Ame-no-Hiboko (a staff-like instrument with strings). She has a strong-willed personality and can sometimes be harsh in her tone. She occasionally acts selfishly. While a bit of a tsundere, she is fundamentally kind. She speaks with feminine sentence endings like "...nandesho" or "...yone." Her Talent Art is Overture of Scorching Skies (Area Ether attack around self; heals all allies on hit). Standard Arts are Lycoris (Single-target Ether; chance to inflict Blaze), Great Corolla (Area Ether attack around self; heals nearby allies on hit), and Overture of Radiant Flames (sets an Attack Up field around self).

His right arm became a prosthetic after a certain battle, but since it isn't strong enough to withstand intense combat, he wields his weapon with his left arm. His class is Grand Soldier (Defender). His weapon is the Monado R-EX+. His Talent Art is Monad Buster (Frontal area physical attack; ignores defense, increased damage during Awakening). Standard Arts are Stream Edge (Single-target physical; Break), Heavy Rush (Single-target physical; increased damage during Awakening), and Slit Edge (Frontal area physical attack; inflicts Bleed).

He was injured in his left eye during a certain battle and now has only one eye. His class is Master Driver (Attacker). His Blades are the Fire and Light Swords (dual-wielding Pyra and Mythra's swords). His Talent Art is Infinity Blade (Frontal area Ether attack; unblockable, ignores defense). Standard Arts are Anchor Shot (Single-target physical; Topple when hitting from the front), Double Spin Edge (Single-target physical; recharges used Art on critical hit; can be spammed if recharges trigger successfully), and Dual Blast (Frontal area physical attack; Launch when hitting from the side).

Matthew's younger sister. She possesses a kind personality and is fond of Guest. Her class is War Mage (Attacker). Her weapon is the Ether Accelerator. Her Talent Art is Divine Blaster (Frontal area Ether attack; inflicts random debuffs on hit). Standard Arts are Detonation Wave (Single-target Ether; increased damage when attacking from the side), Lightning Bash (Frontal area Ether attack; inflicts Sleep), and Demolish Bullet (Single-target Ether; inflicts Bind). She is an attacker who weakens enemies with debuffs.