This Seeking Guide will explain how you can complete all 10 White Nevron side quests and get the best rewards. By doing so, you will unlock the Aiding the Enemy trophy and achievement.
To be safe, avoid attacking any of the White Nevron quest givers, as doing so may result in locking yourself out of a quest and/or prevent you from getting the best loot.
You can find the video guide, with the time stamps and details, of all the quests below:
(0:00) Jar Quest at Spring Meadows (Abandoned Expeditioner Camp)
You can find the Resin for Jar in the lower section of the next area, hidden behind breakable cates. After giving it to him, shoot the lamp that he is holding to light it.
(2:35) Demineur Quest at Flying Waters (Coral Cave)
You can find the Intact Mine to the right of Demineur. You need to do a bit of jumping to get to the item.
(4:39) Bourgeon at The Small Bourgeon
You need to give The Small Bourgeon a Bourgeon Skin, which is dropped by the giant Bourgeon bosses that can be found throughout the game. There is one nearby in the Flying Waters dungeon if you haven’t beaten it yet.
(13:39) Hexga at Stone Wave Cliffs (Tide Caverns)
You need to find three Rock Crystals, which can be collected after you break the crystals in the caverns. You should see one when you take the rope down. The other is located on a hill that you can get to. The third is on the Rocher boss when you approach the rope that leads to the mansion.
(19:25) Troubadour at Stone Quarry
Troubadour will “attack” with red and green notes. Dodge the red notes and let the green notes hit you.
(22:28) Portier at Esoteric Ruins
For Portier, you need to get through a small maze where you have to shoot crystals to open new paths. Refer to the video to find the proper solution if you can’t figure out the maze.
(28:32) Danseuse Teacher at Frozen Hearts (Glacial Falls)
For the Danseuse Teacher, you need to parry all the projectiles. She will attack from the top, middle and bottom angles. The bottom attacks are faster, which may mess up your rhythm.
(30:24) Benisseur at Red Woods
For Benisseur, you need to drop Chroma (money) into the fountain. You will need 90,000 in total to complete this quest.
(32:55) Blanche at The Fountain
After you complete the eight previous quests, talk to Blanche. You should get 100 Colours of Lumina if you helped out the other White Nevrons without killing them.
Otherwise, you will end up fighting Blanche, which will result in a lesser reward of 2 Grandiose Chroma Catalysts and Colours of Lumina.
(35:35) Chalier at Floating Cemetery
For Chalier, pick any weapon you want and then fight him. Afterwards, make sure you end his life when he asked you to.
The Aiding the Enemy trophy and achievement should unlock after you complete all 10 White Nevron side quests.