Start by using Lailah’s map action to clear the malevolence at the entrance and then check the Monolith for an AP before taking the eastern branch. There is another Monolith in the next room that you can collect and if you clear the malevolence at the end of the hall you’ll find a chest with a Mango Sorbet .
You can now backtrack to the entrance and take the western path to a dead end with a chest containing a Life Bottle . Continue toward the objective marker for a scene and then return to the altar and examine it to discover the Altar of the Bow , followed by The Arrow Pedestal skit.
In the next room with a Monolith take the western path and check the dead end to the right to gather the Rosemary . Now head west and exit down the staircase to the southwest to reach a new part of the ruins. You can now explore the dead end to find a locked chest, Amber Garment , and Earth Ring and then return to the previous floor and take the eastern path to another staircase.
Head all the way south first, through a set of large double doors, to reach a dead end with an Apple Gel and then backtrack and continue west. When you reach the save you’ll want to continue west to a dead end with a Saffron before you backtrack and continue to the objective marker.
Boss: Giant Centipede
The first stage of this battle is more about survival than defeating the enemies, since they are resistant to your armatized attacks. Keep slashing them with your attacks in the hopes of keeping them occupied, but don’t be afraid to back off and heal the party with your Burst Gauge if needed. After some time a scene will occur and then you’ll enter round two.
Armatize straight away and stay at range while using your water-based attacks to push the enemies back. If an enemy gets too close you can cast Bubble Arrow to create a row of bubbles in front of you, but the main thing you want to focus on is not getting cornered.
After beating the boss Mikleo will join the party and you’ll obtain the Divine Artifact: Water and Mikleo’s Sub Lord Friend title.
You've been through a lot, but this is proof that you're still on the right track.
Take the eastern path to a Monolith and Amber Circlet and then backtrack and take the western path to a dead end with the Devil Wings . You can now continue to the objective marker to obtain the Holy Water of the Falls and automatically return to Ladylake.