If you play Eternal, do the Lunar Shrine event, and you'll get a 2nd Resplendent Spark!

To get an XP boost, I decided to quickly farm the Lunar Shrine event with one of my Eternal character (my first, and the one I like to play the story mode with) and I was surprised to get another spark with the 10th cache. So, if you still play eternal from time to time, farm that event at least once there!