A Paperback Hero said:
For the card 'Shrine of Nurgle' :
1) does the corruption effect happen to all the opponents attackers that are damaged and
2) does this effect only occur to attackers attacking the zone the 'Shrine of Nurgle' is in play in?
3) Also does damage stick to unit cards once they receive it?
I took the liberty of inserting the numbers and reformating the questions for ease of answering.
1) I would say yes, because it says "after an opponent's unit."
Stated differently, it can be written thus: any opponent whose unit takes damage in combat...The key here I think is the fact that the unit has to take damage in combat to be corrupted and not out of it (like from non-combat damage, action effects from tactics or units, etc).
2) I would say no, because there is no mention of such a restriction. The only restriction is that it's a forced effect that only conditionally triggers when the card is placed in the Kingdom zone. Usually a restriction like you mention would contain the phrase: "corresponding zone" (see page 17 of the rulebook). It does not in this case.
3) Corrupted units are treated just like any normal units except that they cannot attack or defend (page 17 of the rulebook): so yes, they can take damage and the damage received "sticks to" the corrupt unit cards.