The Darkhorse Pirates

I'm forming my own One Piece style crew on here. I'm Captain Darkhorse, a rookie pirate worth 228,000,000 berries. I ate a Mystical Zoan Devil Fruit which allows me to become Hell's Steed, a regular sized demonic horse with teeth that tears flesh. Like Chopper, I can take on forms from Centaur (where I wield a great axe), to a human with a horse head (with teeth than can bite through steel like Arlongs), and Demonic Horse, where necrotic flames follow me wherever I ride. In Human form, I have mastered some haki, which allows me to fight the Marines and elude them. Like Moriah, I feed off death and my power increases when I enter a bloodlust mode, destroying everything in sight. Now, enough about me, what are your backstories and powers?