Romeo is a lean, yet slightly muscular young boy, 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. Like all Dragon Slayers, Romeo possess pronounced canine teeth. 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. After Natsu disappears together with the Team Tenrou 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 demeanor, 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.
Flame Dragon Slayer Magic: Romeo is a Second Generation Flame Dragon Slayer, meaning he found and implanted a Dragon Lacrima within himself, gaining similar abilities to that of Natsu Dragneel's Fire Dragon Slayer Magic. Flame Dragon Slayer Magic is a type of Dragon Slayer Magic that grants the user various characteristics typical of a Fire Dragon: lungs capable of spewing flames, scales that grant protection against fire, and nails covered in flames. Consequently, Fire Dragon Slayer Magic allows the user to produce and control fire from any part of their body, which can be used both in melee and as a ranged form of offense. The generated flames can be manipulated in a wide variety of ways, their “type” can be changed at will, and they can even be given a material consistency. Such fire seems to have a “blunt” effect to it, seemingly causing bludgeoning damage alongside burning. The fire produced by this type of Magic produces much more heat than a standard one, with even the user’s body temperature being capable of melting iron and burning off poison and stigmata's; not only that, but the user’s fire is strictly connected to their feelings, meaning the more emotional they get, the more their flames will increase exponentially in temperature, something that is referred to as “Flames of Emotion”, just like Natsu when his fire gets stronger from the anger he unleashes gets stronger as well. In addition, the user can consume external sources of fire to restore their body to a healthy state and regain their reserves of strength, something that also makes them immune to most types of fire, due to their capability of nullifying fire-based attacks by sucking them in and eating them; the consumed fire also seems to possess a different “taste” according to its “quality”. However, the user can’t eat their own flames, or things set on fire by them, to reinvigorate themselves. Also, as a Second Generation Dragon Slayer, Romeo can form scales on his hands, arms, legs, cheeks and neck area of condensed, solid fire that scorch anyone and anything they touch.
- Flame Dragon's Roar: Romeo's signature Dragon's Roar. He generates flames in his mouth, then releases it in a concentrated line of destructive fire. Unlike Natsu's Fire Dragon's Roar, his roar has a wider range and has greater control over it.
- Flame Dragon's Iron Fist: Romeo engulfs his fist in flames, and then punches his opponent with great force, causing heavy blunt damage on contact. He also uses it to enhance the power of his punches.
- Flame Dragon's Claw: Romeo ignites his feet with flames to increase his kicking power, aside from inflicting burn damage. The flames can also be used for jet-propulsion purposes.
- Flame Dragon's Wing Attack: Romeo rushes towards his target and grabs them, before subsequently setting hands ablaze, sending them flying.
- Flame Dragon's Swirling Horn: Romeo lights his entire body ablaze and headbutts the target at high speed.
- Flame Dragon's Firing Elbow: After Romeo ignites the tip of his elbow, he uses that mix to strengthen his fist and rockets the opponent high in the air with an uppercut attack.
- Flame Dragon's Crushing Fang: With his hand lit ablaze, Romeo swipes at the target in a claw-like fashion, burning them, leaving a trail of burn marks behind.
- Dragon Slayer's Secret Art:
- Purple Fire: Romeo creates a purple flame in his hand that can stick to objects. It was first seen against Thibault as a fireball, but extinguished by him with a puff.
- 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: This fire has a similar effect to actual Lava, as it almost instantly melts through most substances it impacts.
- Rainbow Fire: The user combines the different "colors" of their Rainbow Fire Magic into one, alleged, "deadliest flame". Upon hitting its target, it causes an 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 Fire Magic or Dragon Slayer Magic, apparently making them stronger for more destructive attacks.
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 formerly boasts a high level of magic energy. After becoming a Second Generation Dragon Slayer through both gaining a Dragon Lacrima and unlocking his Second Origins, Romeo now boasts a great deal of magic power, almost higher than Wendy's, who is a First Generation Dragon Slayer that uses Sky Dragon Slayer Magic. His magic color is orange-red.
- Macao Conbolt (Father)
- Fairy Tail
- Team Natsu
- Gajeel Redfox
- Strauss Siblings
- Wakaba Mine (Uncle figure)
- Makarov Dreyar (Guild master)
- Lamia Scale
- Twin Dragons of Sabertooth
- Yukino Agria
- Atlas Flame
- Toshiro Hitsugaya (Best friend and friendly rival, close as brothers)
- Toshiro Hitsugaya (Friendly rival)
- Ryuha Armament Alliance
- Future Rogue Cheney
- Balam Alliance
- Garou Knights
- Legion Platoon