Although exceptional circumstances may lead to someone wielding several
One of the defining rules about Stands is that someone may only have one Stand (at a time). Although Stands may take different forms, or be split into several entities, no one is able to summon several Stands at once.
Originally Answered: Is it possible for a character to have two stands in JoJo's Bizarre Adventure? Yes it is, but there's only a few instances of this occurring. One example that comes to mind is in Part 4, (spoilers) where the character Rohan Kishibe is exposed to a parasitic stand, and as a result gains said stand.
Pucci has only one stand, and it is White-Snake. However, because of White Snake's broken-as-hell ability, he can get other stands by stealing them from their user.
King Crimson is the Stand of Diavolo, the alternate personality of Vinegar Doppio in Jojo's Bizarre Adventure. King Crimson is said to be the most remarkable Stand due to its ability to erase time and predict the future.
In addition, Dio gained access to a second stand through the use of Jonathan's body; this unnamed stand bears a resemblance to Hermit Purple of Joseph Joestar, and has the ability of divination.
On the surface, Stone Free is essentially a close-range Stand with incredible speed and strength, much like Jotaro's extremely powerful Stand Star Platinum, highlighted even further in the similarities between their respective punch rushes.
Dio provokes Pucci to steal his Stand “The World” from him, saying that he can become the “King of Kings.” Pucci refuses Dio's offer because he doesn't want to harm someone he admires.
7 Stone Free
It is a close-range Stand, which is very strong physically. Stone Free allows its user to turn parts of their body into string. Jolyne can use this ability to unravel her arms and legs, which increases her attacking range.
And that's a significant difference: Hamon is a human skill-based craft, whereas a Stand is an evolutionary by-product of mental strength regardless of the organism. Therefore, the two can interact, but they are not intrinsically related.
A Stand is invulnerable to any harm except against another Stand or if their Stand User is harmed, as stand damage and user damage are linked, and one will be hurt in the same way as the other with few exceptions. Stand powers like healing or aging affect both stand user and stand itself. Stands possess intangibility.
Only Stand Users can see Stands. To non-Stand Users, a Stand in action most likely resembles an invisible psychic ability, like telekinesis. Stands are bound to a user's body. Some Stands are bound to objects, however.
The best-known Stand in the series, Star Platinum belongs to Jotaro Kujo, one of the main characters in the show. Star Platinum outshines most other Stands in the series in terms of speed and power.
Summary
Black Polnareff is one of the few characters in the JoJoBA universe who wielded 2 Stands at the same time.
While Stands can (apparently) fly, it's never directly said why certain Stands can fly or can't. Koichi's Echoes Act 2 can fly for no reason, and he uses it to scope out an escape when captured by his soon-to-be girlfriend.
Dio provokes Pucci to steal his Stand “The World” from him, saying that he can become the “King of Kings.” Pucci refuses Dio's offer because he doesn't want to harm someone he admires. Dio apologizes to Pucci for bringing up the idea and confesses that no one has ever put him at ease like Pucci.
Appearance. The bone's particular shape and the presence of two round eminences (corresponding to the so-called sesamoid bones) indicate that it's DIO's first metatarsal bone, i.e. one of the bones within the foot behind the big toe.
The Green Baby is a creature born from a combination of DIO's Bone and the souls of criminals within the prison. The baby's birth is part of the plan created by DIO and put into action by his ally, Enrico Pucci.
Gold Experience Requiem's ability to nullify all harmful actions means it is essentially invincible and makes it the most overpowered Stand in JoJo's Bizarre Adventure.
11 Jonathan Joestar: The First & Weakest Of Them All
Fittingly enough, Jonathan Joestar is the weakest of his family. This shockingly gigantic young lad was the main character for the first-ever "Bizarre Adventure," Phantom Blood.
Khnum is truly the weakest Stand in all of JoJo's Bizarre Adventure. Its ability is Transfiguration, allowing its user to take the appearance of another person. The problem is that Khnum gives its user no additional abilities.
Hermit Purple is known as the 'Hamon User's Stand,' since DIO is able to use a variant of Hermit Purple due to him being in Jonathan's body. This is also because Araki commented that if another Stand User had met Joseph or Jonathan, they would appear to them with the purple vines surrounding them.
Remember when Joseph and Avdol meet Jotaro in jail and told him that Stands were a manifestation of life force? That's the same principle of hamon and that's the reason DIO isn't immune to them.
3 STANDS ARE BETTER: Their Powers Are More Extreme
Hamon makes the user stronger, but it hardly works on any level beyond physical strength.