SPOILER WARNING: Part 5 spoiler details may follow.
Trish Una (トリッシュ・ウナ, Torisshu Una) is a main character and ally featured in Vento Aureo.
Trish is the estranged daughter of Passione's Boss and Donatella Una, being a target for the Boss' numerous enemies, she is bodyguarded by Bruno Bucciarati's gang. She eventually awakens her own StandSpice Girl and grows into a valuable ally for the team.
Trish is a 15-year-old girl of average height and slim build. She wears her light hair (often depicted as pink) in a loose whirl atop her head.
Trish wears a dark brassiere connected to a necklace patterned in tiles of alternating shades of mathematical symbols. She wears a long skirt of similar design, split at the top of her left thigh, and a pair of knee-high small-heeled boots without any legwear underneath.
Personality
Trish is first introduced as a spoiled, selfish girl; this is later revealed to be a way to hide her insecurities, although her self-doubt is still apparent in instances such as expressing her nervousness to Bucciarati whether she and her father would get along or not. Over the course of the time she spends with the group, a deeply loyal, determined side of her is revealed. When she discovers her Stand Spice Girl with the help of Giorno Giovanna, she comes to terms with her own power to defend herself and her new friends. She is also seen lightheartedly teasing and joking around with Guido Mista towards the end once she is comfortable around him, implying that this is her true nature.
Abilities
Trish has been shown once to be adept at self-defense, easily reversing Narancia's knife back onto him when he threatened her, stabbing his cheek.
Trish's humanoid Stand is Spice Girl, of good melee attack and defense, with the unique ability to soften any object (to the quality of a springy cushion) and making them nigh indestructible.
History
Background
Trish was living a normal life alone with her mother Donatella Una before she found out that her father was the Boss of the powerful gang Passione when her mother Donatella passed away. Despite her high-class tastes, Trish seems to have lived in humble living conditions.
After Donatella, Passione found out about her parentage, and she became the center of attention of two factions: firstly her father's loyal underlings who tried to secure her, and then La Squadra di Esecuzione who wanted to kidnap Trish to get to the Boss. Agents loyal to the Boss quickly took her but the traitor assassins continued trailing her.
Vento Aureo
Trish disguised as a janitor
First seen disguised as a janitor, Trish is introduced as the boss' daughter that is put under the eye of Polpo's replacement capo, Bruno Bucciarati along with his gang members Narancia Ghirga, Pannacotta Fugo, Guido Mista, Leone Abbacchio, and Giorno Giovanna. Trish herself is being hunted down by assassins that have betrayed the gang in order to be used as leverage against the Boss. Initially acting spoiled towards her protectors, she slowly but surely forms bonds with the men that consistently put their lives on the line for her sake.
During Bucciarati's battle against la Squadra members Prosciutto and Pesci, Pesci holds Trish hostage and attempts to kill the other members. Though Bucciarati defeats him, Trish is left confused as to the strange abilities and beings coming from the fight. Bucciarati takes this as a sign of her Stand slowly manifesting, beginning with a large claw mark left in the ground.
When she finally got to meet her father, she is knocked unconscious after having her hand severed and is nearly killed by him, were it not for the combined efforts of Bucciarati and Giorno. Upon regaining consciousness, she learned that he actually wanted to kill her so that all his ties with the past would be erased, including the people related to him. Bucciarati and his gang (with the exception of Fugo) would turn traitor against Passione in order to protect Trish and defeat their former boss.
On a plane bound for Sardinia, where Trish knows her father comes from, the group is attacked by the invincible Stand Notorious B.I.G.. Mista and Narancia are severely injured and incapacitated, while Giorno sacrifices both of his hands in an attempt to get rid of the Stand, leaving him unable to use his Gold Experience's abilities. When all the gang but Trish retreats into the cabin, she is attacked by Notorious B.I.G. once more. Though she tries to escape, she notices that one of the ladybug brooches from Giorno's outfit is on the floor and slowly turning into a hand. Trish realizes that if Giorno is to ever use his Stand power again, she has to protect the hand from the enemy. Though anxious and scared, she tries to reach the hand by using the reclining seats of the plane to distract the motion-detecting Stand. Notorious B.I.G. ends up grabbing her by the boot, causing her to panic.
However, the boot almost unnaturally slides off of Trish's foot without letting the Stand touch her. Slightly confused, she leaves a claw mark on an arm rest where she sets her hand down, and begins hearing a feminine voice speak to her, telling her that she's chosen to protect Giorno and the others. A new Stand appears before Trish, introducing itself as her own: Spice Girl. Grabbing the brooch and retreating into the plane's back closet, Trish stops Notorious B.I.G. by softening the door, then a clock when the Stand breeches the door. Spice Girl attacks the enemy Stand by stabbing it with a pipe while it's distracted, but Notorious B.I.G. manages to reach and consume the plane's engine, sending the plane into sharp descent. Making a run to the front of the plane with the enemy Stand chasing after her, Trish uses Spice Girl to rapidly punch and break off the pilot's cabin, with Notorious B.I.G. in the rest of the plane exploding. A small remain attaches itself to Abbacchio, causing Bucciarati to use Sticky Finger's arm to get it off. Trish uses Spice Girl to sever that arm, sending Notorious B.I.G. into the sea as she bids it an "Arrivederci".
Trish eventually learns of her father's name: Diavolo. Arriving in Rome, Trish senses his presence and becomes paranoid, warning the gang of him. She then takes part in the battle against him to take the Arrow, and initially has her soul switched with Mista's via Chariot Requiem. When Diavolo's soul also jumps to Mista's body, he takes near-complete control. However, at a most crucial most when he tries to grab the Arrow, after having deflected some of Mista's bullets, Trish reveals herself conscious. Using her power, she also reveals that she softened the bullets to make it look like they were blocked, and by undoing the softening, the bullets alongside their momentum are restored, shooting Diavolo through the hand and knocking the Arrow far away from him. Trish then tells her father that she'll overcome the fate she inherited, and will no longer cower or flee.
However, Diavolo, in a moment of complete hatred for his daughter, punches Spice Girl through the abdomen, which sends Mista's body flying through the air in the direction of the Arrow. Trish's soul begins to ascend due to the fatal blow, and Diavolo has put himself on the path for capturing the Arrow. In the nick of time, Bucciarati sacrifices himself to destroy Chariot Requiem, allowing her soul to return her body and save her life while forcing Diavolo's soul away. Regaining consciousness, Trish warns Giorno that Diavolo is trying to escape, which inadvertently leads him to attack Giorno to save his own pride after hearing the comment. However, Giorno has already pierced Gold Experience with the Arrow. Trish then bears witness to the awakening of Giorno's newfound Stand, known as Gold Experience Requiem, and watches as her father and his seemingly invincible Stand ability are finally defeated.
Skeptical that Diavolo might still be alive after being sent into the nearby river, Trish urges Giorno to look for him. However, he diffuses her worries with confidence that Diavolo's fate is final. She accepts the response, she decides to go with Mista back in order to see the Coliseum for themselves with the battle over.
(The information below derives from a Light Novel not written by Araki. As such, it may or may not be considered canon.)
In the light novel Purple Haze Feedback, it is revealed that after the events of Vento Aureo, Trish pursued a career as a successful pop star when Fugo hears her singing on the radio. In an interview with her after her song is played, she gives her thanks to "an amazing group of people" that she couldn't have been there without, referencing her time with Bucciarati's gang.
Trish makes her game debut on the PS2 Game, as the only female playable character, voiced by Natsuki Rio.
Much like Giorno and Bucciarati, Trish's main move is her Stand cry attack, being Spice Girl's WANNAABEE, her other abilities allow Spice Girl to make anything it touches softens (such move only works on Super Story Mode, for other Modes the same move is used for a stronger attack), a dash flying kick that sends the opponent far away and Trish can also use a piece of pipe to make a lower attack (the same pipe she used to attack Notorious B.I.G.).
Trish is playable on chapters 14 and 15 during Story Mode. In both battles, she faces two different sizes of Notorious B.I.G. - a small version and a bigger version. At the beginning of chapter 14, Trish can't use Spice Girl; after reaching the other side of the plane, she is allowed to use the Stand. For the second battle, the player needs to survive two minutes against a giant version of Notorious B.I.G.
As a Stand User, Trish is one of many characters with wildly varied abilities that grant her uniqueness in battle.
A trait exclusive to Trish is that she is immune to being wall-splat; at any time she is knocked into a wall, Spice Girl's ability will instantly activate and cause her to recover immediately, making it more difficult for her opponents to combo her. Spice Girl will also trap larger stage objects, making them repel opponents that touch them.
Style Action - I made it softer!: Trish summons Spice Girl to punch the ground, creating a softened spot indicated by a pink glow. Opponents that step on these areas take damage and are bounced high into the air or into nearby walls. Trish may have up to 3 traps active at a given time.
Being this soft means I'm even stronger!: Spice Girl softens and grabs the ground, pulling it up and creating a temporary shield. Any attacks from Trish's front will be reflected back onto the attacker, sending them flying. Projectiles reflected will be aimed at their source, including moving opponents.
Spice Girl!: Spice Girl unleashes a barrage of 11 punches, sending opponents caught flying on the final hit.
With the strength of a thousand fists!: Spice Girl pulls out a metal pipe and swings it down. If it connects, the opponent it knocked into the ground, where the Stand will proceed to stab them using the end of the pipe, before knocking them away. This attack can also hit opponents that are down. If the activating button is rapidly pressed, the attack can be extended to make Spice Girl stab the pipe into the target up to 4 more times. Trish is invincibile once the attack connects.
EX - Being this soft means I'm even more unbreakable than diamond!: The skill activates instantly.
EX - Spice Girl!: The skill activates quicker and Trish can cancel the attack into another skill while Spice Girl is punching, including the normal version of itself.
Dual Heat Attack - WAAAAAAAANNABEEEEEEEEEE: Spice Girl softens the ground where the opponent is standing, shaking them off-balance. Using this opening, Trish charges at the opponent as her Stand delivers an uppercut, before punching them hard into the softened ground. As the target is bounced into the air, Trish jumps towards them and Spice Girl unleashes an upward barrage of punches while letting out its cry, finishing by punching them away.
JoJolities
This is your ability!: Trish must connect her Style Action twice. (200 Points)
Destroy!!: Trish must connect "Spice Girl!" 3 times. (200 Points)
Well... That's certainly got some flavor to it...: Trish must connect "With the strength of a thousand fists!" 3 times. (300 Points)
Being this soft means I'm even more unbreakable than diamond!: Trish must use "Being this soft means I'm even more unbreakable than diamond!" 5 times. (500 Points)
Alright, you piece of trash!: Trish must Retire an opponent with a Dual Heat Attack. (800 Points)
She is paired with Bucciarati in the Eyes of Heaven Tournament, having been placed in the F Block series of battles to be incorporated into the main Tournament. They defeated Diavolo and Joshu Higashikata in the first round, and Part 4 Jotaro Kujo and Diego Brando from Another Universe in the second, being incorporated into the main branch. In the semifinals, they defeated Giorno and Mista in the first round, but were eliminated by Jolyne Cujoh and Gyro Zeppeli in the second.