There are also special limited time Brilliant Events that include unique Registry Page, Brilliant Foundables, and Special Assignments.
You will need to complete the Special Assignments and bring the Brilliant Foundables to the registry before the event ends to get your special rewards.
You'll see Brilliant Traces, similar to the normal ones, but they offer up bigger prizes.
You must claim rewards before the event ends. If you earn them and don't claim before the event is over, you will lose them.