Dio Brando is the main villain of the first arc, Phantom Blood, and the third arc, Stardust Crusaders. His legacy reverberates throughout the JoJo universe. Dio is cruel, narcissistic, and megalomaniacal. Ever since he discovered the true power behind the stone mask, he developed an unquenchable thirst for power and world domination.
Dio Brando is the son of Dario Brando, an alcoholic, selfish, and lazy man who he despised. In 1868, Dario Brando discovered that the carriage that belonged to George Joestar, father of Jonathan Joestar had fell off a cliff. Dario wanted to steal George's belongings but George assumed that Dario wanted to help him. George was grateful to Dario and gave him money.
Dario invested in a hotel business that failed and worked his wife to death.
Dio had nothing but hate and contempt for his father for killing his mother. 12 years later, Dio slowly poisoned his father to death and Dario told Dio to seek adoption with George.
George adopted Dio into the Joestar family. There, Dio met Jonathan decided steal the Joestar family's assets. Dio and Jonathan grew up together and Dio had always bested Jonathan in every endeavor. After they graduated, Dio started to slowly poison George as well.
Jonathan, who was working as an archaeologist, discovered a stone mask and brought it home. Dio discovered that the stone mask gave vampiric powers to the one who wears it. Jonathan discovered that Dio had been poisoning George. Dio wore the stone mask, turning into a vampire and engaged in mortal combat with Jonathan. The Joestar mansion was destroyed in a fire and Dio suffered a grievous injury.
Sometime later, William Zepelli reported to Jonathan that Dio had survived and was recuperating at a small town called Windknights. Dio had devoured the people of the town to recover and had created minions to defend him. After a long struggle, Jonathan landed the fatal blow on Dio and obliterated his body. Zeppeli had lost his life along the way.
On the boat back home, Jonathan discovered that Dio had severed his head and his last minion had carried him to the boat. Dio shot a vitreous humor from his eyes at Jonathan, dealing a fatal blow. Jonathan decided to destroy the boat by exploding the engine so that he would die with Dio. Dio severed Jonathan's head and took his body then hid in a coffin to survive the explosion.
In 1983, the coffin was discovered by a group of fishermen. There he met Enya Geil and she decided to help him. She gave him Stand powers with the bow and arrow where he developed his Stand, The World.
He met Jean Pierre Polnareff and implanted a mind-control parasite on him to control him. He also met a priest, Enrico Pucci whom he befriended and shared his philosophy with. Later, he discovered Noriaki Kakyoin and implanted a mind-control parasite on him as well.
In 1987, Dio retreated to Egypt where he stayed to recuperate while learning about his Stand. He recruited many minions and sent them to defeat the Joestar family.
When the group finally reached Dio's lair, night had just fallen. He took the battle to the city. Kakyoin lost his life to Dio to learn The World's ability. He then conveyed the message to Joseph who then relays the message to Jotaro.
The final battle between Dio and Jotaro took place in the city streets. During the fight, Polnareff attempted to attack Dio but fled immediately after realizing the vast difference in power. Dio also absorbed some of Joseph's blood to power up greatly. During Dio's final attack of dropping a steamroller on Jotaro, Jotaro discovered his Stand's ability to stop time as well and escaped the attack. Jotaro then landed the fatal blow and defeated Dio once and for all.
Dio has several illegitimate children, including Giorno Giovanna who became the main protagonist of the fifth arc, Golden Wind. Dio's other 3 children became antagonists of the sixth arc, Stone Ocean. Enrico Pucci whom Dio befriended became the main villain of Stone Ocean.
As a vampire, Dio has superhuman strength, speed, and endurance as well as the ability to walk on walls and ceilings. He sucks blood through his fingers. He is also able to instantly freeze things on touch and fire high-pressure vitreous humor from his eyes that can easily cut through human flesh and bone.
Dio lost most of his vampire abilities after the events of Phantom Blood.
Due to his body belonging to Jonathan Joestar, Dio has minor telepathic abilities with people of the Joestar lineage. Dio can also use the Stands that are latent within Jonathan's body, which is Joseph's Hermit Purple.
Dio's Stand has superhuman strength, speed, and accuracy as well as the ability to stop time for a brief period. During time stop, only Stand-wielders with the same ability will remain conscious. So far, only Jotaro and his Star Platinum shares the ability to stop time.
Dio's battle cry is "Muda Muda" and his cry is "WRY", which is shared with his son Giorno Giovanna.