Increase required AP to learn spells from espers

Hi! i edited the hex code to make require 255% for learning a spell, instead of 100% the problem is that it's displayed in an ugly way:
As soon as it reaches 100% it returns to 0%, that happens a second time and finally when it reaches 55% the spell is learnt...

Example:
1) The percentage is 94%
2) I get 10 AP;
3) Now it's displayed 6% on the screen (the actual value is 104%)
4) After 2 cycles(> 200%) at 55% i learnt the spell.

What i want to know is... what/where i need to edit to being able to display as percentage value numbers above 100% ? (101% to 255%)

Code:

C3/5027: A0 0C 00       LDY #$000C    Needed to clear the now further over '%' for blank spots

C3/5073: 4C A6 5A       JMP $5AA6    Abuse the now modified code for space saving

C3/50A0: 80 DD          BRA $507F    Need to clear the now further over '%' for non-blank spots

C3/5AA3: 20 E0 04       JSR $04E0    This block is what actually adds the third digit
C3/5AA6: A5 F7          LDA $F7
C3/5AA8: 8D 80 21       STA $2180
C3/5AAB: EA             NOP
C3/5AAC: EA             NOP

C3/5AC2: A9 B6          LDA #$B6    This block is for learned spells % display
C3/5AC4: 8D 80 21       STA $2180
C3/5AC7: A9 B9          LDA #$B9    Changed this way would show 255%
C3/5AC9: 8D 80 21       STA $2180
C3/5ACC: 8D 80 21       STA $2180
C3/5ACF: 80 E6          BRA $5AB7

I believe this covers everything, let me know if there are any issues.

While i'm learning the spell, the percentage rises until 254%
But when i learn the spell then all learnt spell show 200%, in the screen which shows which spells an esper can teach you... what coult it be?

My fault, this:
C3/5AC7: A9 B4 LDA #$B9

#$B4 is what it normally is, #$B9 is what you should change it to.

Yup, now it works!

Thanks for help, i'll credit you for this in my CotG hack.
PS. there's no risk that this code might change anything else, right? (unwanted changes, i mean...)

PS. there's no risk that this code might change anything else, right? (unwanted changes, i mean...)

Correct, to the best of my knowledge and testing nothing else should be affected by these changes.