Hito Hito no Mi, Model: Devil (Maxr7)

Introduction
The Hito Hito no Mi, Model: Devil is a mythical zoan type devil fruit that allows its user to turn into a full or half devil.

Appearance
What did the Devil Fruit look like before it was eaten?

Usage
How does that character use this Devil Fruit? How does it function? Does this character use this Devil Fruit any differently from the previous user?

Strengths
What are the greatest benefits that this Devil Fruit gives to the user? What advantages does the user get from eating this particular Devil Fruit, that makes him/her special when compared to an ordinary person?

Weaknesses
Aside from the standard, universal Devil Fruit weaknesses (falling into large bodies of water, having Seastone attached to him/her, etc.,) what other, inherent weaknesses does this Devil Fruit present to the user? What does the user have to be cautious of?

Attacks
List your Devil Fruit's amazing, spectacular attacks here!

Trivia
Tell us fun facts about your Devil Fruit.