Church says:

Kingdom. Opponents cannot target your units with card effects unless they pay an additional 1 resource per effect.

Shrine says:

Kingdom. Forced: After an opponent's unit is damaged during combat, corrupt that unit.

Let's say that during combat I can damage 4 opponent's units. How much should I pay to activate the shrine? Since the effect is one I'd say 1 resource, but the target are 4, so my opponent says 4 resources... which is correct? What if I have 2 resources left?

tnx, D

You pay zero. The Shrine does'nt target anything. The Forced Effect simply resolves on all units damaged during the 5 Steps of Combat. The only cards that target something are those that specifically use the word "target."

That's sweet!! Thanks a lot.

No problem.