One Piece: What Are The Advanced Haki Forms?

gamerant.com:

Haki is a major source of power in the One Piece world. Although explained properly shortly before the two-year timeskip, this power existed in the story from the very first chapter of the series, where Shanks used it on the Lord of the Coast. With time, more focus was thrown on Haki. The Skypiea arc introduced fans to Mantra, another name for a type of Haki in the Sky Islands, and shortly after, characters such as Sentomaru, Rayleigh, and the members of the Kuja openly started using this ability.

Shortly before the two-year timeskip, the concept of Haki was explained to the fans as Luffy began his training with Rayleigh in Ruskaina. Simply put, Haki is a spiritual power that exists within everyone in the One Piece world. However, only a handful of people manage to awaken this power. With training, Haki can usually be advanced to extreme limits and after the timeskip, One Piece has explored the many advanced types of this power as well.

One Piece: Why Most People Never Awaken Their Haki

To understand the advanced forms of Haki, the very basic forms of the power need to be fully understood first. Haki is generally classified into two types — the Color of Observation, also known as Observation Haki, and the Color of Armament, also known as Armament Haki. Both these Haki types make use of the user's spirit in unique ways. Observation Haki allows a person to access a sixth sense and gain abilities such as precognition, sensing emotions, power levels, and even reading the intent of others. On the other hand, Armament Haki allows users to manifest their spirit as an invisible armor and use it to increase the power of their attack as well as defend. Armament Haki also allows the users to make contact with the real body of a Devil