To the average human, all of them moved at Usain Bolt speeds and Hiromi was the first to reach as she was the closest to him.
It was clear that Hikaru was a parasite-infected and after he displayed strength by crushing Juro's fist with one hand, she wasn't confident that she could beat him alone and so decided to grapple him from behind. If he was immobilised, it would give enough time for the others to take him down.
As if he had eyes on the back of his head, he jumped off the stairs and onto the dining table where Luffy was closest. Luffy crossed his arms in front of his chest like an X-shape as he was fast enough to see Hikaru about to kick him.
However, Hikaru did a turning kick which struck him on the right side of his arm and blew him into the wall next to the front door. A trained eye would see the difference between a sidekick and a turning kick. Luffy's painful consequence is a result of his lack of battle experience despite his increase in his base strength and speed.
A wind blew past Hikaru but it wasn't an attack. Mami was fleeing to the back door. A spike bone erupted from Hikaru's hand and was long enough to be a short javelin. He drew back his arm with the movements of a professional Javelin thrower. He had recently absorbed a past Olympic athlete and received 1% of his total skill and experience.
Although he obtained little muscle memory, Hikaru remembered information on proper standing throw mechanics from his victim's training and visual memories from his throws. Also, all the experiences of more than ten thousand of his victims' middle school sports activities in javelin combined with his unnatural athletic ability made his throw equivalent to a professional player.
As Mami was a metre away from the back door, a bone javelin blew a huge hole in her leg and pierced through the door. The bone javelin kept her leg stuck to the door. Hikaru watched her yell in agony. He didn't miss her vital spots. This was her punishment for fleeing.
His strength had increased a lot compared to when he was in the battle royale in the gym. He could have broken Luffy's arm in that kick but held back because he aimed to test his new abilities and theirs. Mami gave a look to Juro who understood her thoughts.
"Hiromi, go get the chainsaw from the shed while I distract him," ordered Juro.
Luffy got up from the floor with pink-skinned wings that looked like giant webbed hands. They had sprouted from his back while he was on the ground.
Juro's right arm had transformed into a pink fleshy tentacle which he threw at Hikaru. A level 2 tentacle sprouted from Hikaru's back and blocked it. When they collided, Hikaru's tentacle exploded in the air. Blood and gunk fell from the sky.
Seeing this, Juro sneered. Luffy who was reluctant on attacking, charged in after he got some confidence from Juro's successful attack. Luffy slashed with his wings. There was something shiny at the edge of the wing.
Hikaru stepped back and summoned more tentacles from his back. He used one of them to block Luffy's slash. His tentacle got bisected. The edge of Luffy's wing was a sharp blade.
Luffy who did a test attack grinned and relentlessly struck with his wings. At the same time, Juro struck from a distance with his whip. Hikaru dodged Juro's attacks by moving backwards in a Z maneuver while blocking Luffy's wing attacks with two bone spikes. He was duel-wielding them like swords.
His bone swords were scratched and cracked by Luffy's wings. Luffy's wings must be made of a harder material than bone. Bone has a hardness value of 5 on the Mohs scale. A fingernail has a value of 2.5, while a copper penny is 3.5. Diamond is one of the hardest materials and has a score of 10 on the Mohs hardness scale.
The bones in a living person are actually alive. The bone itself is living and could grow and resorb bone. It was more accurate to say that there are four types of "bone cells" which all have different roles in the manufacture and regulation of bone.
The structure of bone is made up of collagen fibres where mineral crystals like calcium hydroxylapatite are deposited. The tensile strength is due to the collagen component while the compressive strength, rigidity and hardness come from the mineral crystals.
The clubbing appendages of a mantis shrimp uses an extremely dense form of calcium hydroxylapatite which gives it a high impact resistance. Similarly, but in excess, Hikaru changed the ratio of calcium to phosphate in the mineral crystal and minimised the number of cells that are naturally interwoven in a bone.
This way, he removed any hollow space in the bone.
It is so dense and hard that it exceeded a Mohs scale of 7, yet it was still cracked by Luffy's wings. The only weakness of Hikaru's highly dense bone is it can break easily by tension forces (pulling). However, no one could tell that easily from its appearance.
Hikaru blocked a strike from Juro's whip by crossing his two swords to his front. The strike broke his two bone swords. Hikaru looked at Juro's arm. It was swollen and pink. It looked like Botan's enhanced arm.
As he recalled, Botan was able to make a giant fist from the enhanced arm. Juro could do the same maybe but he guessed that the giant fist was Botan's specialisation while Juro could manifest whips. Normal bone can be broken by a karate chop from a karate master. It was only natural that his highly condensed bone could be broken by an attack from an enhanced arm.
Hikaru jumped high onto the first floor above him.
"Luffy no!" Juro called out.
Luffy flew to chase after Hikaru as he had air superiority but when he rose above the handrailing, Hikaru was waiting for him with bone javelins in hand.
*Thck Thck Thck*
Luffy tried dodging but there were too many javelins being thrown at him.
Bones continuously ejected out from Hikaru's hands which he grabbed onto and threw them.
One hit Luffy in the stomach and then another pierced his wing and pinned him to a wall. After that more javelins impaled him until he looked like a pinned-up butterfly specimen.
Juro appeared from the stairs beside him.
"You killed my BOY, Luffy!!"