Spirit Power Grade System
Rank 1 - 10: Spirit Scholar
Rank 11 - 20: Spirit Master
Rank 21 - 30: Spirit Grandmaster
Rank 31 - 40: Spirit Elder
Rank 41 - 50: Spirit Ancestor
Rank 51 - 60: Spirit King
Rank 61 - 70: Spirit Emperor
Rank 71 - 80: Spirit Saint(Will get Spirit Avatar)
Rank 81 - 90: Spirit Douluo
Rank 91 - 94: Title Douluo
Rank 95 - 98: Super Douluo
Rank 99: Limit Douluo
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Spirit Ring Classification Base on there Age:
White: 10 Years Spirit Ring
Yellow: 100 Years Spirit Ring
Purple: 1,000 Years Spirit Ring
Black: 10,000 Years Spirit Ring
Red: 100,000 Years Spirit Ring
Gold: 1,000,000 Years Spirit Ring
Optimal Spirit Rings :
1st Spirit Ring : Less than 423 years old Spirit
2nd Spirit Ring : Less than 764 years old Spirit Beast
3rd Spirit Ring : Between 1,300 ~ 1,800 years old Spirit Beast
4th Spirit Ring : Between 3,000 ~ 5,000 years old Spirit Beast
5th Spirit Ring : Around 12,000 years old Spirit Beast
6th Spirit Ring : Less than 20,000 years old Spirit Beast
7th Spirit Ring : Between 30,000 ~ 50,000 years old Spirit Beast
8th Spirit Ring : Between 50,000 ~ 100,000 years old Spirit Beast
9th Spirit Ring : More than 100,000 years old Spirit Beast
However, In the case of a million-year-old spirit rings, it may appear in different colors depending on the attribute.
(Ex: Iceblue, Dark Red Gold, Dark Grey, Green Gold, etc.)
But all of this is but a rough guide however. The true factor to that determines what the maximum age of a spirit ring that could be added is the spiritual power of a person. Every person has a set amount of mental capacity or "mental space" which the spirit ring(s) in question will occupy, where the amount of space the ring will occupy will increase with the ring's age. Regardless of the rings themselves, if there is enough space, the ring will be accepted into the martial soul (assuming its attributes don't clash with that of the martial soul itself). And although one's cultivation greatly increases one's mental space, it is ultimately independent of it.
Spirit Bone :
Torso Bone
Skull Bone
Left Arm Bone
Right Arm Bone
Left Leg Bone
Right Leg Bone
External Bone
* Reference: Soul Land Wiki Fandom