Hai Hai no Mi (Hope Universe)

The Hai Hai no Mi  is a Logia-type Devil Fruit which allows the user to become, manipulate, and control ash(volanic ash, to be precise), turning the user into a Ash Human (灰人間, Hai Ningen). "Hai" (灰) means "ash" in Japanese. In the English version, it is called the Ash-Ash Fruit.

Appearence
The Hai Hai no Mi looked like a gray Watermelon with swirls before it was eaten.

It has similar traits to sand, consisting of small fragments of volcanic rocks, minerals, and glasses like obsidian so it's color is predominately black.

Strengths and Weaknesses
Ash is burnt matter, meaning that burning it again will not do much, if anything at all, as such it is a great counter for fire. The ability to create virtually anything would have to be the fruit's main strength, it can be produced from various parts of the body and hardened into a dense form that can crush an opponent in its grip, apply blunt force damage, or even be sharpened to cut them. Constructs are also a big strength of the fruit. This takes time, however, and surges of water as well as big gusts of wind can disrupt the process before it is finished. The dense ash can also be broken by a strong enough impact, the strength of it being determined by the user.

Another interesting ability of the ash logia is to increase the temperature of the ash they produce, to a searing degree. Obviously not to the degree of something like magma, but easily enough to get the job done. Simiar to other fruits that can generate heat, extreme temperatures do not bother the user of the Hai Hai no Mi.

The fruit has a very conflicted "rivalry" with water because of this. Enemies can drench themselves in the liquid, or any liquid for that matter, and be capable of bypassing the usual Logia defense. If the user themselves in drenched in water, however, they can heat up the temperature of the ash to evaporate the liquid. Other than that, the fruit only has the normal Devil Fruit weaknesses.

Trivia

 * Raiden often brags that he's capable of hardening his ash to be as tough as steel.