Thanks for the comment/feedback. I'm glad you liked the tables! I will try to make that advancement rule more clear in the near future. But you can remove corruption spending advancements points. It costs more if you have more corruption (each 3 tiers/level). For removing 1 corruption point only, you must spend 1 advancement point for every 3 levels of corruption you already have. If you have up to 3 corruption, you spend 1 advancement point to remove 1 corruption (1:1 ratio). But if you have 7 corruption, to go from 7 to 6 of corruption, you must spend 3 advancement points (3:1 ratio). Then, to go from 6 to 5, you need more 2 advancement points (2:1 ratio).