I like Rex's idea more, so I'm gonna work off of that instead.
Sex Pistols Requiem is now a full-size, single-bodied close-range power-type that looks like an ordinary Sex Pistol, albeit with the proportions of Mista. The number on its forehead is 4, signifying Mista resigning from attempting to control his fate. By letting go of his paranoias and allowing his life to steer him in the right direction, he weaponizes the misfortune that he used to fear.
Sex Pistols Requiem gains the ability to manipulate the concept of fortune and misfortune, allowing it to alter the probability of events occurring by imbuing Mista's bullets with chance-alteration properties. In a sense, he gains bullshit plot armor which allows him to trigger events that would've been realistically impossible otherwise (say, causing the ceiling to collapse by shooting it and striking a weak point in the foundation or killing someone instantly by shooting them at just the right angle that one of their ribs is dislocated and punctures their heart).
Infant's idea was really cool, so im gonna ad onto that.
So Sex Pistols requiem is going to be a stand that is about the same height and build as mista's like many of these theories are, but instead of just controlling fortune, since he is much bigger, he can lift heavier objects. Maybe even have a possibily of it having the ability to make more that one Sex Pistol for a small amount of time. I also feel like it's ablilites of controlling fortune would be able to effect the type of ammuninion he can hold, like lets say Mista has a grednade launcher. He shoots a grenade out of it, and S.P.R catches it, He makes another Sex Pistol, and the firts one throws it, the next one catches it, now normally the grenade would blow up the moment it makes contact, but due to the luck/ plot armor, Mista and the bullets are fine. So S.P.R #2 can just shot put the grenade at an enemy, and just like that, it blows up, and the enemy dies.