Suggestion by Seifalda
These ranks allow them access to kido and other abilities.
Beginner Kido: 1-35
Intermediate Kido: 1-65
Advanced Kido: 1-99
However, to stop for example a unseated officer using black coffin or bankin I suggest that profiles be graded with a tier and these tiers lead to points.
These are the tiers I suggest
Low Level
Medium Level
High Level
Master Level
Almighty Level
Each of these is divided into
Weak
Medium
Strong.
Understanding one's Power Tier is the first step in understanding just how many spells your character can learn or produce, and how often. These lead to points like I said
Low-Level - 5 (Academy Student, spiritually aware human, trainee quincy, hollow)
Mid-Level - 10 (Unseated Officer, Normal Quincy, Low level Arrancar)
High-Level - 15 (Seated Officer(Weak/Medium), Vice-captain(strong), Skilled Quincy, High level arrancar (weak/Medium) Low level espada(strong) Adjuchas(medium) Menos grande(WeaK))
Master-Level - 20 (Captain, High level espada, Genius Quincy, Vasto Lorde)
Almighty-Level - 30 (Aizen, Genryuusai etc)
Then more points are added due to your kido expertise.
Kido Level - Beginner - +0
Kido Level - Intermediate - +5
Kido Level - Advanced - +10
The last points are added due to whether you are weak average or strong.
Weak - +0
Average - +2
Strong - +5
So an Almighty Strong Character with advanced kido would have 45 points (this is like Aizen level) whereas a low level weak character with begginer kido would have 5 points (this is like academy student)
Each kido spell would use points so even if your advanced and technically able to use black coffin you wouldn't have the points. Points are like your amount of reiryuoku.
Levels 1 - 9 = 2 Point
Levels 10 - 19 = 4 Points
Levels 20 - 29 = 6 Points
Levels 30 - 39 = 8 Points
Levels 40 - 49 = 10 Points
Levels 50 - 59 = 12 Points
Levels 60 - 69 = 14 Points
Levels 70 - 79 = 16 Points
Levels 80 - 89 = 18 Points
Levels 90 - 99 = 20 Points
So basically even if you did have 45 points you could only use Black Coffin twice before you would be restricted to using a 4 point kido spell. Otherwise you'd be out of reiryoku and collapse.
This system also works for other abilities. For example if two people with zanjutsu advanced went against eachother and one had a higher tier e.g. one was HL-S and was HL-W then the HL-S would most likely win in a swordfight unless the HL-W was really skilled at roleplaying and managed to overcome their weakness.
Of course, it would need to be worked out a bit better to include Ginto(Quincy spells), hollow attacks (Bala, Cero) and other things, but it would make fighting easier.