Zangetsu appeared behind Liu Zheng to attack him with his sword but Liu Zheng easily blocked and both of them started to fight with their sword displaying exception degree of comprehension of the dao of sword as well as such meticulous control over their sword that it has surpassed the realm of Sword as an extension of body and reaching the realm of Sword body Unification where one's mind, body and sword are one.
Both of them utilized Sonido and Hirenkyaku, appearing at several places on the island fighting with all their strength with the only difference is that even though Zangetsu is more powerful than before Liu Zheng is still on par with him.
Zangetsu formed 30 quincy bows and 30 quincy arrows towards Liu Zheng and he cut through all of them in what seemed to be an instant and fired a huge getsuga tenshou at Zangetsu which was cut in half by the later.
None was willing to the other even an inch and the fight continued for hours with none of them getting an advantage over other.
After one point, Liu Zheng fired a huge Qi attack on Zangetsu and saw him faltering for a second after blocking it. He used this chance to get behind him and slash his back with his sword but what he was met with blew his mind.
When Liu Zheng appeared behind Zangetsu, he was cut at seven different places on his body and without getting a chance to fully take in the situation he was kicked hard in his stomach and pushed so hard that flew until he hit a huge rock destroying it.
Zangetsu just used the Void Slash on him and he couldn't understand how
"I did tell you that you need to use every technique you have and you were just wasting time here fighting with only sword techniques and soul race techniques. So i had to remind you properly. You have to overcome yourself and me in every aspect to be able to defeat me."
He pointed his fingers towards Liu Zheng fired the void beam which Liu Zheng immediately dodged but Zangetsu kept it going and just changed its direction to where he appeared next, cutting everything in its path in half.
Liu Zheng fired his own void beam, both of them colliding in the middle and distorting the space as well as creating multiple mini space cracks.
From his other hand Zangetsu launched many space blades but were promptly slashed in half using Void Slash.
The battle was starting to get frustrating because now Liu Zheng felt like he was fighting himself but opponent used his powers even better than him.
Whenever he tried to do any kind of long range attacks they were neutralized by zangetsu by opening a temporary space tear and letting the attack pass through it.
He couldn't even outmatch him in speed since both of them knew sonido and hirenkyaku as well as in terms of mastery Zangetsu was slightly better.
And the void slashes were all cancelled out incautiously as if two Sukunas were fighting each other.
Knowing that there is no chance of winning this way Liu Zheng decided to do what a sane person would usually never do in the middle of fight.
He ran away using sonido with full speed while zangetsu anticipated that he would attacked and made preparations to block it was confused as the attack never came.
By the time he realized Liu Zheng was already outside the island. Zangetsu did not understand why he was running away since he knew Liu Zheng wasn't one to give up so easily but the matter of the fact was that he wasn't ready for a bankai at all. Even though he really needed it, he wasn't strong enough to defeat him thus not ready for it yet.
Zangetsu decided to play along with it and tried to find him. On the hand after making enough distance Liu Zheng was stumbling in the air after every few seconds for some reason.
Sometimes he would disappear and right after that he would appear without any balance falling downwards where later he would find balance after a few moments flying away from the island again. In the process he got so far away from the island that zangetsu had to search in many directions to be able to find him.
It took him about half an hour to find Liu Zheng but he finally came into his sight but as soon as he did, he disappeared again. Appearing some distance away from where he was before and then flying away as if he sensed Zangetsu's presence.
Zangetsu tried to close their distance but as soon as he gets closer Liu Zheng disappears again, appearing further from him stumbling for a moment and then flying way again. He tried to understand what Liu Zheng was trying to do which at first seemed to be a faster sonido but discarded that idea as such a fast sonido at this realm would harms the user itself and then thought of teleportation but Zangetsu also had the same level of space force comprehension and knew that it was impossible.
Due to the wide gap between them, Zangetsu's divine sense couldn't reach him, making him unable to understand what his opponent was up to.
After about 15 minutes , Liu Zheng stopped disappearing but soon he started to do another bewildering thing which was to leave many small and large space cracks in zangetsu's path.
Zangetsu believed it to be a trick to slow him down and he skillfully dodged all of them was now able to slowly get closer and closer to Liu Zheng.
"Running away won't help you in defeating me Liu Zheng. This will just prolong your own defeat. At this point you should already realize that you cannot attain bankai right now and need more time so let's just end this." he said trying to convince Liu Zheng to end this meaningless battle.
Liu Zheng stopped right after hearing zangetsu and replied "Yeah, it is time to end this but not the way you want it to."
"It looks like you have found a way to defeat me then let me see it." As soon as Zangetsu said that Liu Zheng vanished from his spot leaving behind a space crack and the next moment 20 other space cracks appeared all around him. All of it happened so fast that he wasn't able to reach and was now trapped inside for a few seconds as it takes a bit of time for space cracks to disappear.
He remained vigilant for any kind of attack because in this state of entrapment Liu Zheng could attack from anywhere when suddenly a void beam came from behind him which he skillfully blocked by countering it with his own.
It actually came from a space crack and he believed that Liu Zheng hid there to take advantage of his situation and sneak attack him by hiding in the void which was useless as their attack power levels were mostly the same but another void beam from above, and then another, then another and another.
Zangetsu tried his best to block all of these void beams but the number kept increasing every next second and soon he was attacked from all 20 sides with a void beam coming from each and every space crack, rendering him unable to defend and leaving him full of holes across his body.
As the space cracks were closed on their own, Liu Zheng appeared in front of him with his finger target on zangetsu's head ready to destroy him completely at any second and said
"Didn't I say It was time to end it, Zangetsu? So, do you admit defeat?
"Yes, we do Liu Zheng. You win" Zangetsu closed his eyes and replied as there was no further point in continuing the battle and at that moment both of them learned the name of their Bankai.
Both of them smiled and Liu Zheng helped him go back to his knowledge sea.
On the Island inside The Knowledge Sea,
Zangetsu and Old man were separated again and fully healed after half an hour as their power continued to rise.
Liu Zheng entered his knowledge sea as he sat beside them and asked "So, how are you guys feeling now? I didn't go too hard on you right?"
"Nah, we are completely fine now King. In fact stronger than ever. So, tell us how were you able to do that ?" Zangetsu(white) asked and old man expressed his curiosity too.
"It was actually quite simple. We were almost equal in every regard whether speed, strength, durability, techniques everything. So, defeating you like that was impossible and I at least needed higher strength and speed to be able to defeat you.
Speed without more strength will just damage you a little while until you adapt too it and gaining more strength in that short period of time was not possible.
For speed i experimented with a theoretical technique i have been thinking about which was to make a movement technique using space force and use it to fold and unfold space to be able to travel at much higher speed than what my cultivation realm allows me during a battle."
Liu Zheng replied and continued
"And as complicated as it sounds, it was as much harder and impossible to achieve in such a short amount of time and even now i haven't grasped it. I instead created a much simpler and weaker version where i utilized space force instead of qi in a way similar to sonido to create distortion of space and increase my speed by a long margin while also keeping me undetectable while moving and end position unpredictable.
Now that i had speed, i still needed more strength and since i couldn't increase my internal strength i decided to use external strength and best place to get more space force is the void so while i was running away from you i created many space cracks as we could both instantaneously create a space crack but maintaining and utilizing is was not something we had focused on and that is what i focused on then and you conveniently ignored them as traps in your path which worked pretty well for me.
So in the end i used the spatial step/sonido to speed blitz you and using the element of surprise to my advantage moved all around you in 5 more steps creating multiple space cracks with each step and overwhelming you with void beams I launched from controlled spheres of space force hidden inside the space cracks while amplifying them with space force from the void."
"Hmmmmm, sounds like some sh!t you have done king though i don't understand it at all but it does make you sound cool and smart." Zangetsu replied scratching his head.
"To be able to learn all these things amidst battle as well as think so far ahead and effectively apply them. I have to say that i underestimated you a lot but you surpassed my expectations of you which makes me proud." Old man said with a rare smile on his face.
"Haha, even I didn't know I could do that but you underestimating me did help me a lot and helped me understand there is a lot of advantage in being under estimated too."
"I never underestimated you greatly Liu Zheng. You could say that underestimating is a wrong word for this situation and you truly surpassed yourself which was the main thing needed to defeat us as I had said in the beginning."
"I guess you are right old man. But we don't have time to rest as the clouds are gathering outside at an alarming rate covering the whole island and it hasn't stopped yet. So be ready, This time is going to be much harder."
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The reason I didn't use Swordsmanship which MC trained in for a month is to keep the element of Old Man Zangetsu having a fragment of the grand dao of sword but unable to utilize it fully relevant.
The Mc will continue to improve in the Dao of Sword and Old man is going to play a big role in it.
And our MC might create his unique Void Sword Art or Space-Time Sword Art in the future.