Thieves guilds are a common sight in many campaigns and many modern rogues can also use magic. This means that the Phantom Thieves of Heart could be remade in Dungeons & Dragons, in order to steal the hearts of enemies, but i🃏n a more literal "cutting it out of their chest" sense.
Roguish characters who have a secret identity have appeared throughout the history of fiction and the fantasy genre is no exception. D&D has this in spades, as it's easy to hide someone's true identity with the aid of magic items or spells. As such, a character like Joker from Persona 5 could easily exist in somewhere like Faerun or Oerth. There are many corrupt and evil societies that exist in D&D universes (Thay, the Empire of Iuz, pretty much every city in Athas), and these have their own rebel factions that seek to overthrow the powers that be. Joker and the Phantom Thieves come from a game set in contemporary society, but they could be brought into many D&D worlds as members of groups who work in secret to take down powerful political figures. The Phantom Thieves use a mixture of combat abilities, stealth, and magic with an elemental focus. They're not conjurers (that would be more appropriate for a Shin Megami Tensei he🦩ro) but can tap into magic through the force of♓ their personality.
The version of Joker that we have created uses material from the Player's Handbook. Joker is a non-variant human who is a multiclass rogue/sorcerer, who takes on the Arcane Trickster and Wild Magic archetypes. His stats would be centered around his agility and personality. Using the basic stat spread listed on page 13 of the Player's Handbook and taking his race into consideration, Joker'♛s starting stats would be STR 9, DEX 16, CON 14, INT 11, WIS 13, and CHA 15.
Joker's Background, Alignment, And Class
As someone who lives a dual life, the perfect background for Joker would be Charlatan, which gives him access to the vital False Identity feature, allowing him to act in secret and maintain some semblance of safety from the ಞauthorities. His starting skills would be Deception, Sl𒊎eight of Hand, Acrobatics, Investigation, Stealth, and Intimidation, as well as proficiencies with the disguise kit and Thieves' tools. His gear would include a dagger, a hand crossbow (it's doubtful the DM will be cool enough to let the player have a gun), leather armor, a Burglar's Pack, Thieves' tools, a disguise kit, and a forgery kit.
Assuming the player keeps their rogue/sorcerer levels about even across the run of the character, the main choice they would need to make over the course of his development would be Metamagic abilities. Joker's best options would be Distant Spell, Quickened Spell, an🔥d Silent Spell. If the variant Feat rules are used, then the best choices for him would be Alert, Actor, Crossbow Expert, Defensive Duelist, Inspiring Leader, or Lucky.
Joker's alignment is a bit trickier and a lot of it depends on t🐬he player's interpretation of the character. The Phantom Thieves discuss (at grating length) the philosophical and ethical implications of their actions, but they keep entering the Metaverse and screwing with people's brains. What right do they have to mentally invade the miꦦnds of unwilling people in order to force them to change their personality? Depending on the player's perspective, you could argue that Joker is Chaotic Good, based on the fact that he only targets evil people who themselves are up to shady stuff, as they are often forced into action by outside circumstances, but his methods might put him closer to the evil side of the spectrum.
Joker's Spells
Joker's magic is provided to him by the Personas he uses in battle. These give him access to elemental damage spells and protective magic. Joker also exhibits other abilities that can be duplicated with 🍷magic, such as inhuman agility, the capacity to influence the thoughts of others, and the ability to see through illusions. Using the multiclass rules and combining the spell progression of the Arcane Trickster and the Wild Magic sorcerer, a level 20 Joker could only ev𝓀er reach a maximum of level 7 spells, and his list would only come from the sorcerer & wizard classes.
With those guidelines in mind, Joker's spell list would benefit from mage hand, true strike, minor illusion, fire bolt, expeditious retreat, find familiar (for Morgana), jump, burning hands, magic missile, thunderwave, witch bolt, misty step, alter self, detect thoughts, blur, invisibility, knock, scorching ray, spider climb, suggestion, nondetection, haste, nondetection, fireball, lightning bolt, sleet storm, phantasmal killer, ice storm, wall of fire, greater invisibility, cone of cold, dominate person, teleportation circle, chain lightning, circle of death, true seeing, delayed blast fireball, fire storm, and teleport.
In terms of actual playstyle, Joker would need a different a🥃pproach that characters who only belong to a single class. Like his video game counterpart, Joker relies on hitting hard before the enemy can act using sneak attack and either raining damage with spells or hiding his presence using magic and aiding the party with ranged weapons. Joker doesn't plant his feet and wail on enemies like his allies, as this leaves him vulnerable to counterattacks (his HP score isn't the best). Instead, he combines stealth and magic to keep the enemy off-balance until they are defeated.
The multiclass rules in the fifth edition of Dungeons & Dragons are considered to be underpowered compared to characters who focus on one class, and that's true for most combinations of classes from the Player's Handbook. It's not all about stats and being the most min-maxed character in the world, however. There are some people who have an interesting character idea and want to live it out, even if their DPS isn't up to snuff. A character like Joker is tailor-made for certain settings, where the players have to face off against an oppressive society, like Barovia in Curse of Strahd. A character who mixes stealth and magic together in order to wage a secret night war, while maintaining a day job that keeps them safe from the law enforceme🗹nt, would make for some very interesting adventures indeed. It's up to the player to make♉ sure they keep their identity a secret and make sure that when combat happens, the enemy will never see it coming.