This achievement is story-related and can't be missed.
After finding Ive and bringing her to the party, she'll ask the group to help her rescue Taika -- her yellow pet that you met on the prologue.
At some point, you will then be tasked to go to the Burning Desert, where Taika supposedly is being held. Upon arriving there and fighting your way under the deadly sun (be careful!), you will see an Onurasi statue (the "frog" used to save game and fast travels) under a big structure.
Approach this spot and a fight should start. Defeating the enemies will make Taika free from her cage and the achievement should unlock right away.