Just like what Rayleigh said to Luffy in the manga, Haki is the embodiment of will, with only pure training, unless you are gifted with extraordinary talent, or you are lucky enough to catch some trick, otherwise, the improvement of Haki will be very slow and if you want to make Haki become much stronger, the best way is to fight against the strong people.
It took Luffy two years to master Haki to the initial level but after entering the new world, it took only a few battles to master the highest level usage of the three types of haki and he even awaken his devil fruit.
The same goes for El, after being hit by conqueror coating few months ago, he quickly master the method of using conqueror coating.
Now, after being repeatedly slashed, he successfully upgrades his observation haki and gains another ability, Future vision.
Counting his innate mind-reading ability, he is now at the top of the world when it comes to observation haki.
Even if it's Shirahoshi with the same innate observation, Kuina with radio waves amplification and Fujitora who has his observation haki boasted after blinding himself out of sorrow for all the evil he had seen, they can't be compared to El, because Mind reading combined with Future vision, how terrifying will El's observation haki be
El used Life Return (Seimei Kikan) to increase the control of his body to the extreme, then he wrap his sword with high-level armament haki and slash at rayleigh at a very fast speed.
Facing E's attack, Rayleigh is still the same as before, using his Future vision to find El's flaws while blocking his attack, but the next second, at Rayleigh's body a sound of clothes being torn apart sounded.
While using Future vision, it was as if Rayleigh saw some dangerous situation, so almost the moment when sounds of his clothes being torn apart sounded, his figure suddenly distanced from El at a very fast speed.
Looking at the hole in his clothes with a little blood seeping out, it was thanks to his timely use of Armament haki that he was not totally cut in half, then he look at El in front of him and ask with some curiosity.
"What did you just do That's not like Future vision at all."
"I don't know what is it, I only follow my feeling just now and it feels wonderful."
After successfully slashing Rayleigh, El did not pursue his victory, but recalled the feeling just now, with an intriguing smile on his face.
"If you have to describe the feeling just now, you can call it invincible."
Just like what Rayleigh said, his sword slash just now was not future vision or mind reading at all.
When mind reading, future vision, and Life Return (Seimei Kikan) are combined into a single ability, his every attack would reach the first level in the world in terms of control, reaction speed, and explosiveness.
Life Return (Seimei Kikan) ability allows him to turn his body into shape at any time, instantly going from zero to full-strength blow or full-strength blow to zero, just like when he throws a punch to Shakky with a full-strength blow, but then the next moment he unloaded his full-strength blow, which caught Shakky off-guard.
If Kaido has such an ability, when he fights Luffy in the manga, there will be no situation where he was beaten too much.
When El proficiently utilizes the characteristics of Life Return (Seimei Kikan), even if his sudden change can be predicted by ordinary people, they will not be able to keep up with El's swift continuous sudden change.
Only by mastering the future vision can they ignore El's sudden change in attack, however his passive ability, mind-reading which is stronger than the future vision, no matter how the other party wants to block or dodge his attack, he will see through them in advance.
The future vision is similar to Mind reading, but their nature is completely different.
Mind reading can see through others' thoughts while Future vision sees what others will do in advance, however, Future vision still has some flaws, it can only see what the other party will do in advance and can't read the other party's thoughts.
If faced against an opponent with amazing feinting skills, they can their amazing feinting skills can be used to crack the Future Vision and if both of them master the Future Vision they can crack each other's ability.
However, after the Mind reading and future vision are used together, they will cancel each other's flaws and create a new ability that can see their future action while reading their thoughts.
Such ability is just like the rule-type devil fruit, it's totally outrageous.
It is such an outrageous ability, what kind of chemical reaction will it produce if it appears in a monster who can freely control his body to continuously change his body swiftly Obviously, just like what El said, he will become invincible.
The sword that slashed Rayleigh just now, was like Shakky who was punched by El, they are both completely caught off guard.
Because El sealed Rayleigh's future vision, the image that Rayleigh can see were all false.
The future has been disturbed by El's future vision and the inexplicable feint blow with the Life Return (Seimei Kikan) at the same time Rayleigh's thoughts were completely seen by him and he just seized the flaws that Rayleigh faintly shows by suddenly changing his attack trajectory while interfering with his future vision which caught him off guard.
Now, El's sword slash is even more incomprehensible than Divine Departure which is adding conqueror haki to flying slash, because his three abilities that are extremely rare in the world are combined to form a new ability.
Unless Rayleigh finds a way to deal with it, or his overall strength is far higher than El's, without the ability to deal with El's new ability, he will undoubtedly lose.
With the promotion of observation haki and gaining a new ability, El's strength has entered a new level, and almost became invincible.
Although I have said it more than once, I still have to again.
As El grows older, his three talents will officially reveal their incomprehensibility.
If any of one of these three talents is missing, for example, if his Life Return (Seimei Kikan), El's brand-new skills will not be so incomprehensible or maybe if he doesn't have the mind-reading ability, even if El masters the future vision and use it together with Life Return (Seimei Kikan), it would not be so outrageous, but there is no if, before the next son of the heaven to sea, the world only favors El.