Hero Artifact: Ren Amamiya/Joker
See my previous Hero Artifact for Shirou Emiya for details on this series
My idea for an artifact for Joker was a set of gloves that allow for demonic magic. Originally it was just one glove but it expanded to two with the abilities which I will explain later.
I went for the demon thing b/c I wanted to expand on how Satanael uses the 7 Sins in the Sinful Shell, so I wanted to split them up into various powers. The claws were added for more detail but could also be used for lockpicking, the Pentagram on the left hand for the demonic theme, and the zero on the other representing the Fool Arcana. The Smartwatch with the Metanav eye was meant to give reference to that important part of the plot and again, I'll explain later. He also can summon the Wings of Rebellion from Smash and can now fire feathers like knives (think Xayah from League of Legends)
For now, I will go over the Powers that I chose to represent this Sins:
Lust: Pheromone Manipulation, Mostly used for causing Sleep/Confusion. Eventually, this power can evolve into complete Biological Manipulation. This power was slightly difficult to decide b/c most Lust powers seem to be gateways to someone's hentai fic and that isn't what I am trying to do, but given this particular sin I guess it's unavoidable
Gluttony: Joker is a nimble thief and not an overeater, plus most mouth/eating-based powers don't fit a classy phantom thief. When I was looking through examples of Sin powers I came across Pyrokinesis, as Fire is also a consuming element (GLuttony is more than just eating). Plus I could see Joker using the flames to aid in cooking, as the magic within it makes the food taste 10x better.
Greed: Supernatural Theivery. Think like Soft & Wet from JJBA, but WAY more limited at first. In the beginning, he can only steal personality aspects, since the Phantom Thieve's whole M.O. is stealing people's distorted desires. This can be done via touch or through phantasmal chains that he can shoot out from the gloves. The stolen negative aspect then takes the form of a jewel. Of course, since the only thing in this jewel is a negative aspect of someone's personality and in the hands of anyone else it would just corrupt them, it's better to just get rid of it. Once the power evolves though, THEN he can steal powers and place them into gemstones. He has found a way to cheat and gain many other powers through this.
Sloth: Again, Joker isn't lazy or anything like that, so I had to be specific. I went with Telekinesis b/c now he can steal from afar and can manipulate the feather kunai better.
Wrath: Curse Weapon Manifestation. With this power, he can use his Eiha/Curse Element in weapons. This curse feeds on the negativity of the target so a normal/good person will only get a headache and maybe a small cold at worst. He can normally just finger-gun it, but if the opponent is armored/super durable then he'll need the weapons to break through. His main weapon can switch between gun and knife form. Combining this ability with his Greed power can allow for creating new weapons empowered by abilities he's taken (For more detail, Say he was fighting Krillin. If he were to use the Greed power absorption on him directly, he'd gain Ki but not know any of his techniques. If Krillin fires the Destructo Disk at him and he absorbs it as it comes at him, he can then use that technique but ONLY, that technique. If he absorbs the Destructo Disk, then places that jewel into a weapon, like a CHakram, then it is enhanced even further, but with the downside of now it is a physical object that can be taken back as Joker needs physical contact to return the weapon back within his glove's hammerspace).
Envy: This one, Greed, and Gluttony can be hard because all 3 share a theme of Absorbing/Copying powers/energy. I went with the simple Shapeshifting like Envy from FMA.
Pride: I don't want to go too BS with this one (I say as I have listed all these abilities for Joker, and that he has more via his Greed power). I went with Intangibility for Pride. I gives me that vibe of "I am above you, you don't deserve to touch me".
I had other ideas for some Sin powers, but those could easily be obtained by the Greed power stealing that power from someone else. SO I am basically cheating, but hey. When do thieves play by the rules?
As for the Metanav app, Joker actually has access to his own little pocket dimension with this power known as "The Underworld" (referencing the Demonic Plane and the Criminal Underworld). It is basically a massive expansion of the Thieve's Den from Royal that he can alter however he likes. Much like the Velvet Room it is between Dream and Reality, so he can access it whenever he likes and can even alter how time flows there. He can even invite his Friends here due to their bonds. There is a cityscape within this dimension sure (forged by Joker's memories of this time in Tokyo and on the road in Strikers), but in the outer areas are where powerful demons can manifest. This is usually used for training and obtaining new powers.
Yeah I went ham with this one sue me.