The REG holds a lot of the rules and addendums that wouldn't go into a rule book.
You should start
with this thread. There, you will find posts about resources, rules, FAQ, and more for easy access.
On the ruling, it is not inconsistent, because in this example you have interrupted the ability of Lions; it is suspended, waiting to reactivate. By the time it does, though, there are no characters to activate it on; it does not reactivate.
In the case of Holy Ground negating Gold Shield, Gold Shield has completed, and nothing is suspended. If you played Holy Ground on the now-Red character, you negate Gold Shield and the character is put back to the correct color. However, Holy Ground was still played on a character of the correct brigade, even if they are no longer. Therefore, the effect still works (and cards cannot indirectly negate themselves, as well). Holy Ground is only discarded because the rules say that if no character matches brigade in battle, it is discarded.
Hope that helps, but interrupt and reactivation always takes a little getting used to
Read over the thread I referenced, and see if that helps you get started and provides you the resources you need.
