
Clair Obscur: Expedition 33 - All Nevron Quests
As you work your way through Clair Obscur: Expedition 33, you'll encounter many dangerous monsters in the world, known as Nevrons. However, some Nevrons you meet will speak with you, seeming less dangerous than their counterparts. These 'friendly Nevrons' are white in color, and they usually ask a favor of you. These are Nevron Quests, and you can earn the Aiding the Enemy achievement for completing them all.
You'll find your first "friendly Nevron" in the game's first zone, in Spring Meadows near the Abandoned Expeditioner Camp flag. He is a Jar Nevron, and he asks you to find a Resin to return it to him. The Resin is found a short while later in the same zone, and once you return it, you'll get a reward. A Healing Tint Shard, in this case. This is essentially your tutorial quest.
One of the later friendly Nevrons, a Noire in The Fountain, much later in the game, will give you some Colour of Lumina as a reward. I believe they might give more Colour of Lumina if they are left alive. I received 100x Colour of Lumina from it. Perhaps I'm mistaken and you get 100x Colour of Lumina regardless, but you can always go back and kill the Nevrons later.
Leave the Chalier for last, since you *have to kill him*. Once you get Noire's reward and the Aiding the Enemy Achievement, then feel free to kill all these Nevrons.
This guide is in progress

Nevron Type | Location | Quest | Reward |
Jar | Spring Meadows | Find the Resin key item in Spring Meadows, give it to the Jar, then shoot his staff. | Healing Tint Shard |
Bourgeon | The Small Bourgeon | Give the Small Bourgeon a Bourgeon Skin, which is dropped by any other Bourgeon. Leave and return to the area for your reward. | Colour of Lumina |
Démineur | Floating Waters | Find the Intact Mine in Floating Waters and return it to the Démineur. | Deminerim (Lune) |
Hexga | Stone Wave Cliffs | Grab three lustrous Rock Crystals in the Tide Cavern area of the cliffs, then return to the Hexga | Auto Shell |
Troubadour | Stone Quarry | Play the Nevron's game. Dodge the red notes and get hit by the green notes. The pattern seems random for each attempt. | Healing Parry |
Portier | Esoteric Ruins | Complete the area's maze to find Wood Boards, then return to the Nevron spirit. | Protecting Heal |
Bénisseur | Red Woods | Pay 5000, 10000, 25000, and then 50000 Chroma at the well here. | Recovery |
Danseuse | Frozen Hearts | Parry all attacks from the Danseuse. | Danseuse Outfit (Lune) |
Noire | The Fountain | Noire will seemingly give you Colour of Lumina based on how many other Nevrons you've helped. | 100x Colour of Lumina |
Chalier | Flying Cemetary | Choose a weapon and defeat him. [I killed him last of the white Nevrons.] | Auto Powerful |