Kenbunshoku Haki was introduced as something simple to us by Rayleigh at first:
However, ever since then (and even before then but it was proved later) we’ve seen one exception and irregularity after the other, which I’ll mention shortly, but we’ve treated them as special occassions. The thing is though, once those special occassions start piling up, the stop being so special. We’re now at a point where kenbunshoku haki, mainly its advanced form, can be broadely separated into the two categories I’m about to mention. Said categories is what we’re going to name Mantra (not just the local name for kenbunshoku at Skypiea) and Foresight.
What does each of those categories entail? Well, Kenbunshoku Haki is best described with 2 words: “Situational Awareness”. What situational awareness is, by definition, is this:
“The perception of environmental elements and events with respect to time or space, the comprehension of their meaning, and the projection of their future status / condition.”
The difference between the two types of kenbunshoku haki lies exactly in the the essence of the words I highlight in the sentence above, time and space. To help you get a better picture, imagine a house with Mantra representing its width and length and foresight representing its height. With that definition and image in mind, let’s move to the actual classifications.
MANTRA
This type represents space and it’s about “how much” a haki user is aware of about the area and people inside their range and “how far” said range can reach. Normally speaking, the range of kenbunshoku haki isn’t too big. We normally see it ranging roughly up to the extend of a building at most. That is normal and all but we’ve seen cases where its range is considerably longer than that.
Coby was able to sense soldiers from all over Marineford (but DIDN’T see Akainu’s fist coming beforehand):
Aisa ( little girl from Skypiea ) could sense people all over a whole island:
Van Augur (Blackbeard crew’s sniper) could shoot at seagulls from a huge distance away:
It’s worth noting that Usopp’s comment was that they had been shot earlier but died later:
However, we see 3 seagulls falling down and Van Augur said that only one died with a time delay:
Usopp was able to clearly see Luffy’s, Law’s and Sugar’s auras from a huge distance:
Those examples prove that what we’re classifying now as “mantra” may be something akin to a whole school ( like a sword style) of kenbunshoku haki that focuses on increasing the range of kenbunshoku haki and getting as much information as is possible within its range ABOUT THE PRESENT. Much like Coby couldn’t see Akainu’s punch coming back at Marinefold, fighters who mostly specialize in mantra type kenbunshoku (mostly snipers or people who awaken being more sensitive to it) have a bigger range, effectively making this skill “multi-target/ area of effect”, of kenbunshoku haki but decreased potency as they can’t read further into the future than basic kenbunshoku haki allows for.
FORESIGHT
This type represends time and it’s about “how far along into the future” a kenbunshoku user can see in regards to people inside their kenbunshoku range and “how vividly” they can visualize it.
We’ve mainly seen Katakuri use this type of kenbunshoku, and he’s able to see the future quite vividly:
And we’ve also seen Luffy developing the same ability, although he sees the future less vividly than Katakuri, at least at first:
I have two more examples based on my personal opinion. Although this is still in a stage of speculation, please pay close heed to the next two examples of foresight as I think they’re very important: