Sumi Sumi no Mi

The Sumi Sumi no Mi is a special Paramecia-type that allows the user to create, control, and transform into Darkness, making the user a Darkness Human (闇人間).

Etymology

 * "Sumi" is from "sumizome", which translates "to dye something black".

Strengths and Weaknesses
The first and foremost strength, as demonstrated by, is that it allows the user to produce and control an abundant mass of Darkness and a unique trait of tapping into the chilling effect of vein of the underworld. The darkness produced takes on the appearance of a pitch-black substance.

As a "special" Paramecia, the user can actually change their body into darkness, akin to a Logia. Other than that the user is affected by the standard weaknesses.

Trivia

 * The Fruits ability to utilize the chilling effect of the underworld comes from the phrase “A trapped soul wondering in Chilling Darkness".