So, it might be that sandai kitetsu gives cursed power (for example asura) to zoro, the cursed power is stored and used by left eye. To prevent over control of this power, zoro might have cut his eye. He didn’t open his eye yet because he didn’t find it necessary to do so. So, finally I conclude that left eye of zoro and his cursed sword sandai kitetsu are responsible for giving demoic,cursed and special move which is hard to control.So,to gets perfect over this power, zoro cut his eye.Remember how Grount was unable to control his hand.
Yeah its DARK KING SILVERS RAYLEIGH
Rayleigh eye is cut too. He is known as Dark King…….why? Well, the word dark is related to demon and curse.Did you find any connection? What if in earlier days of Rayleigh, he too possed the cursed sword.He went out of control and eventually he found solution to control his cursed power i.e. to cut the eye.He finally opened it when he got full control. When he got full control over his power and opened eye, he might have shown very advanced and unqiue dark (cursed) power that earned him the tittle ‘Dark King’. I hope this backstory will make sense.So, far there are many similarities between zoro and rayleigh. Some are:-
Going on same sequence we can assume that rayleigh and zoro share same backstory.Otherwise what might be behind of cutting of eye and the tittle Dark King?
It makes sense if we relate the cut eye and the tittle dark king with the power of curse.
Like how rayleigh got the tittle Dark King, zoro too will through lot of experiences and training will get his Power under control.On his final battle with mihawk, zoro will use deadly special demonic move to finish off Dracule Mihawk and the Tittle Dark King will be given to zoro. Why I think Rayleigh tittle will move to zoro is because they both have same characters and many similarities so far.
I) There are many similarities between rayleigh and zoro like –
1)Dark King Rayleigh is right-hand man of Pirate King and so is zoro but of Future Pirate King.
2)Dark King Rayleigh and Zoro have both eyes cut.
3)Dark King Rayleigh and Zoro both love drinking and both are cool
4)Dark King Rayleigh was best swordsman of his era and Zoro is Future best swordsman.
II) The reason behind the tittle DARK KING might be because of overwhelming demonic move and the full control over the power of curse.
III) Going on same sequence, possibly the tittle ‘DARK KING’ will also be transferred to zoro. That makes zoro the Future Dark King