Romeo is a lean, yet slightly muscular young boy of short stature, possessing prominent abdominal and pectoral muscles and, to a minor degree, biceps. He has straight, yet long dark hair with a spiked style to it. His bangs are particularly prominent, covering part of his forehead, with some smaller strands jutting outwards from the top of his head. He has large eyes and a small, mildly round nose. His red guild's stamp is on his left shoulder.
Romeo wears an attire that somewhat resembles Natsu Dragneel's, likely out of admiration for him and sadness for his supposed death. He wears a long, dark red, sleeveless open jacket with lighter-colored edges that reaches to his low-thighs, revealing part of his muscular chest and held closed around his waist by a light sash, tied by a knot on his left hip. His legs are covered by loose, light-colored pants reaching down below his knees, paired with low, dark laced boots. Around his neck is a light-orange scarf adorned by a wavy motif, mirroring the one which Igneel gave Natsu, but being tied on the front in a large knot. His forearms are wrapped in bandages.
Romeo is a kind and good-hearted boy who loves his father very much. He takes pride in Macao's occupation as a Mage, and makes it his childhood dream to become a Mage himself. He also greatly admires Natsu, viewing him as an older brother and mentor. After Natsu disappears together with the Tenrou team on Tenrou Island and is believed to be dead along with everyone else on it, Romeo becomes a sullen, cynical youth who believes his father to be a coward for doing nothing to defend their guild, and doesn't smile throughout the missing Mages' absence until they return seven years later. As he began to "grow up" in life, he displays a more serious, cool, and mature personality, yet still has the same kind-hearted and valiant soul, willing to help others in need like Natsu, though doesn't inherit Natsu's recklessness and takes his actions more carefully. Having become a Mage of Fairy Tail at this point, Romeo is a proud member of the guild who tries to defend its name from anyone who insults it. Also, when he talks about or with his older guild mates, he ends their name in Nii or Nee.
- Purple Fire: Romeo creates a purple flame in his hand that can stick to objects.
- Blue Fire: A spell in which Romeo creates a blue-colored flame with cold properties.
- Yellow Fire: A spell in which Romeo creates a yellow-colored flame hovering on his palm. This flame apparently gives off a strange smell.
- Red Fire: A spell in which Romeo creates a red-colored flame in each of his palms. When he brings them together, the fire creates a straight, fire-based stream that greatly damages his opponents, as well as causing a wide explosion.
- Rainbow Fire: The user combines the different "colors" of their Rainbow Fire Magic into one, alleged, "deadliest flame". Upon hitting its target, it causes a large-ranged explosion.
Purple Flare: This is variation of Fire Magic, which allows user to create and manipulate specific purple flame, that cannot be extinguished by wind or water. The caster can conjure this type of fire through various parts of their body, such as their arms. Mages can use this magic in different ways, like attack, binding or support.
- Purple Net: The user summons forth their Magic Seal or flame orb, which creates purple flare taking the form of ropes, ensnaring groups of people around them. The form of this spell differs depending on the user, as it can be used as a net rather than ropes.
Expert Hand-to-Hand Combatant: Romeo also revealed some melee skills. He usually strikes with hands and elbows, at least - the legs. He is able to do some acrobatics, such as somersaults, evading attacks, owing to the reaction, as in the situation with Dan Straight. His blows are usually enhanced by either of the two sub-types of his Fire Magic, apparently making them stronger.
Enhanced Strength: Despite his small stature, Romeo possesses a high degree of strength that nearly matches that of Natsu's.
Enhanced Speed: In multiple battles, Romeo has shown enough speed to close multi-meter distances between him and his opponent and strike before they have a chance to react.
Enhanced Reflexes: Romeo has been seen dodging and even catching high-speed projectiles when launched at him (for example, bullets).
Enhanced Durability: Romeo has been seen taking great forces of impact and still being able to stand up with just minor scratches.
Great Magic Power: As a Mage of Fairy Tail, Romeo boasts a high level of magic energy. Through his countless adventures however, has increased his magic power even further, almost matching him near Wendy's magic power. His magic color is orange-red.