Not This Time - Secret Badge

Enter the challenge island, Echo Sequence 1, inside the Nexus Temple, second floor. Turn to the left and run toward the lamp and purple tree-shrub looking thing and go to the edge near a second lamp by the Koda Artwork on the stone pillar. There are "unseen" stones that appear. Hop across them to the hidden portal. You are now in Echo Sequence 2. Complete the challenge to earn the badge, Secret Obelisks!

Now that you are inside challenge island, Echo Sequence 2, go to the left corner again, like how you got to this challenge island. One "unseen" stone will appear. Stand on it, and you now have your second badge, Not This Time.