Backstory & Devil Fruit Powers
Dan the Calamity, also known as Dan of the Speed and Dan the Tornado and his Pirate Name, King, is one of the Calamities for the Yonko Kaido. He is the user of the Hayai Hayai no Mi, which allows him to move his body parts faster than lightning and project wind from his hands. Dan doesn't spam his Devil Fruit powers, but he is useful with them. He is a pirate with the Beast Pirates.
In terms of Design, he is a tall and muscular man being 13'9 and 211 pounds.
In terms of power, Dan is great and hand to hand combat and Rokushiki.
Dan can use the Rokuogan, a blast attack. Really, that's all he can do with Rokushiki aside from the basic techniques.
He is capable of fighting with four swords, two in each hand.
He can use all 3 types of Haki, but Armament is the Haki he's best at.
A blast attack.
Kaze no Shotto (English: Wind Shot)
Dan fires a long blast of compressed wind.
Kuikkufisuto (English: Quick Fist)
Dan causes his fist to go fast, increasing it's power.
Ken (English: The Sword)
Dan makes his sword, Jettsu, move very fast for a sharp attack.
Kyujosho (English: Fast Overwhelm)
Dan blitzes his opponent with a kick. This is his signature technique.
Yori Hayai Attotekina Atto (English: Better Fast Overwhelm)
A Haki Enhanced Version of Kyujosho.
Tatsumaki (English: Tornado)
Dan's most powerful technique, where he creates a tornado from his hands.
Dan the Calamity vs. Eustass Kid and Killer: Win
Dan the Calamity and the Beast Pirates vs. The New World Alliance: Win
Dan the Calamity vs. Monkey D. Luffy: Win
Dan the Calamity vs. Monkey D. Luffy Again: Loss
Dan seems to be a quiet, calm, and relaxed pirate, but acting tough when needed to.