Barbabianca, whose real name is Edward Newgate, is a central figure in the world of One Piece, known as one of the Four Emperors who rule the second half of the Grand Line, the New World. He is a man of immense size and muscle, though he is not a giant but a human affected by gigantism. His most distinctive physical traits are his large, crescent-shaped white mustache, which gives him his name, and his bald head, though in his youth he had long blond hair. He typically wears a large captain's coat with his Jolly Roger embroidered on it, a symbol he also bears as a tattoo on his back. In his later years, his health deteriorated significantly, requiring him to be connected to multiple IV drips and attended by nurses, a condition that did not, however, stop him from drinking large amounts of sake.

Barbabianca's background is rooted in a deep personal tragedy that shaped his entire life. He was born on Sphinx, a poor island in the New World that could not pay the Heavenly Tribute to the World Government, leaving it unprotected and lawless. Orphaned at a young age, he grew up surrounded by the devastation wrought by pirates and human traffickers. This difficult childhood instilled in him a powerful and unusual motivation for a pirate: not a desire for gold or glory, but a profound yearning for a family. As a young man, he took to the seas and joined the legendary and feared Rocks Pirates, serving alongside future emperors like Big Mom and Kaido before the crew's dissolution after the God Valley incident. Following this, he formed his own crew, the Whitebeard Pirates, which would grow into a powerful fleet. He became a great rival to the Pirate King, Gol D. Roger, and was one of the few who could match him in combat, with the two sharing a mutual respect that bordered on friendship. Before Roger's execution, he revealed the secret of the Will of D. to Newgate and offered to tell him the way to Laugh Tale, but Barbabianca famously declined.

Personality-wise, Barbabianca is defined by his fierce loyalty and paternal nature. He considers every member of his crew and allied fleet as his own sons, and in return, they call him "Pops". This family is the most important treasure to him, and he values the freedom to sail the seas with them above all else. He is a man of great honor and dignity, believing that every sailor should live with humanity and considering betrayal the most unforgivable crime. Despite his intimidating presence and legendary power, he is not foolish or reckless, though he is known for his confidence in his own strength and for ignoring the advice of others, such as when he dismissed warnings from Shanks about Marshall D. Teach, also known as Blackbeard. He has a distinctive, booming laugh: "Gurararara!".

His primary motivation throughout the story is the protection of his family. This is the driving force behind his most significant action: launching a full-scale war against the entire Marine headquarters at Marineford to rescue his "son," Portgas D. Ace, who had been captured and sentenced to execution. This act demonstrates that his role in the story is that of a protective patriarch and a pillar of the old era, whose very existence maintained a fragile balance of power in the world.

Key relationships are central to his character. His relationship with Ace is particularly poignant. After Ace spent five days fighting Jinbe, Barbabianca confronted him, recognized him as Roger's son, and invited him to join his crew. Though Ace initially refused, he eventually came to see Newgate as the father figure he never had and dedicated himself to making him the Pirate King. Another critical relationship is with Shanks, another Emperor, with whom he shares a tense but respectful rivalry. When Shanks came to warn him about Ace hunting Blackbeard, their disagreement was so powerful that the clash of their weapons split the sky. His greatest adversary is Marshall D. Teach, a former subordinate who broke the crew's cardinal rule by killing a comrade to steal a powerful Devil Fruit. This betrayal is something Barbabianca considers unforgivable, setting the stage for their final conflict.

Throughout his life, Barbabianca demonstrates a remarkable, if subtle, development. While he is a static figure of immense power for most of the story, the Marineford arc reveals the full depth of his character. Despite his failing health and the betrayal of his ally Squard, manipulated by the Navy Admiral Akainu, he continues to fight to save his family. He shows compassion to his enemies, like when he embraces Squard after the betrayal, forgiving him and understanding he was merely tricked. His death is the ultimate expression of his character: after receiving a mortal wound from Blackbeard and his crew, he dies standing upright, with no wounds on his back, symbolizing that he never retreated from his enemies in his entire life.

Barbabianca's notable abilities are legendary, earning him the titles of "the strongest man in the world" and "the man closest to One Piece". He wields the Gura Gura no Mi, a Paramecia-type Devil Fruit considered the most powerful of its kind. This fruit allows him to create vibrations, generating earthquakes and tsunamis with enough force to tilt an island and split the sea itself. It is said that his power is so great that he could destroy the world. His primary weapon is a massive bisento, a type of polearm named Murakumogiri, which he uses in conjunction with his Devil Fruit powers to deliver devastating blows. Beyond his Devil Fruit, Barbabianca was a master of all three types of Haki. He possessed powerful Busoshoku Haki to strike Logia users like Ace and Akainu, incredible Kenbunshoku Haki that allowed him to sense attacks even while sleeping, and the rare Haoshoku Haki, the disposition of a king, which he could use to overwhelm others and clash with Shanks, splitting the heavens. Even in his old, sickly state, his endurance was superhuman; at Marineford, he sustained hundreds of wounds, including devastating blows from magma and cannon fire, yet continued to fight until his final breath.