This card states:

Building Kingdom. Forced: After an opponet's unit is damaged during combat, corrupt that unit. Now does this cause corruption only when i attack the kingdom because it is attached to the kingdom or whenever one of my cards attacks any section of the chaos area or takes damage from the chaos battlefield?

thanks

Doesn't matter what section, just as long as it was combat damage

Yea, that ability applies globally as long as the shrine to nurgle is in the kingdom - read up on the rules for the nuances of how the card texts work, there are some good breakdowns.