Observation Haki / Kenbunshoku Haki
Tier 1: Ability to sense others auras, power levels, and emotions.
Tier 2: Ability to predict opponent’s action within the users minds-eye to aid with mobility and dodging.
Tier Unique: The ability to see into the future for a certain amount of time.
Armament Haki / Busoshoku Haki
Tier 1: Hardening physical things (body or objects) and ability to bypass devil fruit created defenses or properties.
Tier 2: The ability of repelling opponents with Busoshoku Haki without touching them, like what Rayleigh did when he first demonstrated the Haki to Luffy.
Tier Unique: An even higher grade of this technique causes the user’s Haki to reach inside the target’s body and destroy them from within.
Conqueror’s Haki / Haoshoku Haki
Tier 1: Knock out people with weaker Haki.
Tier 2: Inflict physical damage to objects and people.
Tier Unique: Control over nature. This is seen from when Whitebeard and Shanks clashed and the weather began to change. The same happened when Big Mom and Kaido clashed on Onigashima.