Corrupting an attribute will replace its perks with much more powerful options. As you take on more corruption, your character's health and stamina pool will suffer. The reward for this sacrifice will be powerful moves associated with the attribute that you've corrupted. You may only ever suffer from 50% less stamina and health due to corruption, which is exactly the amount you will suffer from corrupting all 20 points of an attribute. This means that once you've committed to corrupting one, you may as well do the rest.