Hello. I'm really sorry you lost the second Holy bond from the event. We get 50% of the needed points when we open a set of 10 epic bonds, and 50% from opening a Holy bond. So yes, you got one holy bond for the 20 epics, you open, and 50% for the next attempt with your 3rd set of 10 epic Bonds. To be able to get the second holy bond you had to open a holy bond or a 4th set of 10 epic bonds. So, 1 holy bond open gives us the 50% of the points needed, the same 50% is for opening a set of 10 epic bonds. We get the epic bonds from our activity, and usually, we don't spend our precious emeralds on Epic Bonds. It was so since this event was introduced into the game. If you don't understand something, please feel free to ask.