"Zoro has shown a new technique called "Asura" which gives him the appearance of having six arms and three heads, like the deity of the same name. He is also surrounded by a dark aura while in this state and the first time he achieved it, the ground shook and numerous holes appeared in it. This ability allows Zoro to utilize nine swords in combat.
What this ability is, how Zoro attains it, and the exact nature of this attack are currently unclear, but Kaku suggested it was an illusion created by Zoro's spirit."
Zoro's technique is his own. Something created from his spirit. Probably growing from his childhood. Everytime he lost he got another sword hoping that having another one would increase his power. After training his body and spirit so much his soul just reacted to the want for strength and ability. As for everything else Zoro did his strength and speed. They were his own as well.
"Zoro has monstrous physical strength. At a very young age he was able to lift boulders over his head, and is now able to lift and toss an entire building. Zoro's agility, speed, and overall reflexes are also extraordinary. He has shown that he is quick enough to keep up with Sanji, who is a master of his own leg-based style, and with CP9's Kaku's Soru movements, and he himself can move at nearly inconceivable speeds and jump at astonishing heights, even dodge bullets with ease. On numerous occasions, Zoro has shown being able to evade (or block) high-speed attacks and projectiles that move so fast that it would normally be impossible for an average human to even notice them, much less evade them. Thus, Zoro was able to dodge simultaneous pressure shots as well as a laser blast from Bartholomew Kuma, both of which travel at extremely high speed, even after being heavily injured from his previous fights with Oars and fatigued from his fight with Ryuma."
Given all the skills you see that Zoro has you have to keep this in mind. He was the second in command basically of Luffy's crew. He needed to have this kind of strength because of the position they chose to put him in the show. Consider the strength of the Dark King Rayleigh. Who was the second in command of Gol D Rogers. When people saw him the shook in fear because they knew his power. Zoro is like this. Your character sheet looks good just too soon to be so powerful in my opinion. You leave no room to grow stronger through the story.