Yusuke is a member of the Phantom Thieves in Persona 5, yet he might be the most distant member of the group. Yusuke attends a different school from his friends and has to be persuaded before he lets Joker (and the player) grow closer to him. The fact that Yusuke grew up in a sheltered manner and devoted himself entirely to his art has made it difficult for him to bond with other people, which is why his friendship with the other Phantom Thieves allows him to break free of his ice-cold exterior.
Yusuke's icy demeanor is mirrored by his Personas and the kind of magic that they use, which is augmented by a range of physical attacks and speed-boosting abilities. It might be harder to befriend Yusuke than the other members of the Phantom Thieves, but his devotion and skill in battle makes him worth the effort.
How To Get Yusuke In Your Party
Yusuke, code named Fox, is the fourth person to join Joker's party in Persona 5 and his story is part of the main quest, so it's impossible to miss him. Yusuke encounters the Phantom Thieves when he develops an interest in Ann Takamaki and wants to paint a portrait of her, which eventually leads to him joining the group.
The second antagonist in the game is a corrupt artist named Madarame, who has been stealing Yusuke's work and passing it off as his own. It is revealed that Madarame also allowed Yusuke's mother to perish in front of him so that he could steal a portrait that she had made. It's up to the Phantom Thieves to break Madarame's spirit and reveal his crimes to the world, after which Yusuke becomes a staunch ally for the remainder of the game.
Goemon And Kamu Susano-o Persona Powers
Yusuke uses the Goemon Persona throughout the game unless the player manages to max out his Confidant Rank, which will result in Goemon evolving into Kamu Susano-o.
Yusuke's Personas use a mixture of ice-based spells and physical attacks, with Goemon resisting ice and being weak to fire, while Kamu blocks ice, resists wind, but is still weak to fire.
Goemon starts off with Bufu, Giant Slice, and Sukukaja for free; it learns Vicious Strike at level 18, Mabufu at level 20, Counter at level 22, Rising Slash at level 23, Mind Slice at level 27, Bufula at level 29, Speed Master at level 31, Tempest Slash at level 34, Counterstrike at level 37, Mabufula at level 40, Heat Wave at level 43, Deadly Fury at level 47, Masukukaja at level 49, Bufudyne at level 53, High Counter at level 58, Myriad Slashes at level 62, Mabufudyne at level 65, Vorpal Blade at level 69, and Brave Blade at level 74.
If Goemon is evolved into Kamu Susano-o, then it keeps the same abilities and level progression outlined above, but its resistances change and it gains the Evade Fire ability, which triples its evasion chance against fire abilities and spells.
Yusuke's Confidant Quest
Yusuke does not attend the same high school as the other members of the Phantom Thieves (save for Morgana, who is a cat and doesn't go to school), which means that you have to seek Yusuke out in order to create a connection with him and level up the Emperor Arcana.
The player can pursue Yusuke's Confidant quest line on June 18th and he is usually found hanging around in the Shibuya Underground Train Station during the daytime. One of the benefits of developing a bond with Yusuke is that he is able to copy Skill Cards using Blank Cards. In order to be able to max out Yusuke's Confidant Rank, the player will need to have a Proficiency of 4 in order to be able to enter Madarame's house.
Earning the first Rank in Yusuke's Confidant quest will allow him to duplicate low-level Skill Cards, reaching the second Rank will give him the Baton Pass ability, reaching the third Rank will give him the Follow Up ability, reaching the fourth rank will give him the Artist Talk ability (which sometimes gives you a second chance during negotiations with an enemy), reaching the fifth rank will allow Yusuke to duplicate mid-level Skill Cards, reaching the sixth rank will give him the Harisen Recovery ability (which sometimes lets him heal status elements), reaching the seventh rank will allow Yusuke to duplicate high-level Skill Cards, reaching the eighth rank will give him the Endure ability, reaching the ninth rank will give him the Protect ability, and maxing out Yusuke's Confidant Rank will transform Goemon into Kamu Susano-o.
In order to receive the most points from dialogue with Yusuke, the player will need to give specific responses, which are presented here without context in order to avoid spoilers for the dialogue.
The choices in Rank 1 don't matter.
For Rank 2, "It's novel" or "It's Enigmatic", and "I can't wait" or "I hope you're right".
For Rank 3, "Don't let it bother you", "This isn't like you" and either "How Exactly" or "That's the spirit".
For Rank 4, "Why are we in a boat?" or "I should bring a girl here", and "Love comes in all forms".
For Rank 5, "Do you want me to strip?" and either "I'm sure you will" or "It doesn't look like it".
For Rank 6, "It feels nostalgic", and either "Maybe he was sympathetic" or "I couldn't possibly tell you".
For Rank 7, "What do you mean?" and "The truth is within you".
For Rank 8, "It has to be Ann" and "You've really grown Yusuke".
For Rank 9, "Her love for her son" or "The pain of separation", and "You've really changed Yusuke".
The choices in Rank 10 don't matter.
Can Joker Date Yusuke?
This is one of the most popular questions asked about Yusuke and the short answer is "No", with the long answer being "No, but it's probably for the best that he is un-datable due to Atlus' history of poor LGBT representation in their games."
In Persona 5, it's possible for Joker to date his doctor and his teacher, which the game presents in a romantic light, and doesn't question the problematic nature of the teenage protagonist entering into a relationship with a woman who is much older and in a position of authority over him. The game does not allow you to date any of the male party members, regardless of their age, including Yusuke.
All is not lost for the Joker x Yusuke shippers in the world, as the story of Persona 5 is not over yet. The mysterious Persona 5: The Royal could very well be an updated version of the game and it's possible that Yusuke might be a romance option in that game. There are also those who believe that the girl shown in the announcement trailer for the game will be a female main character who takes Joker's place in the story, which means that The Royal might take the same route as Persona 3 Portable and allow the player to date all of the male party members when playing as a girl.