As you near the conclusion of Clair Obscur: Expedition 33, you will stumble upon a small side quest dedicated to Chalier, a Nevron who wants a duel. This quest is one of the last Nevron interactions that you can do, as you will have to fly to the Floating Cemetery.
At this point, your party should consist of Lune, Maelle, Sciel, Verso, and Monoco, with all characters being unlocked. This Nevron quest is a special one because you actually have to kill the friendly quest-giver.
Locating Chalier’s Challenge
To find Chalier, fly west of the Monoco Station with Esquie. You can see the Floating Cemetery from afar, so just head there to kick off your encounter.
While exploring the graveyard, you’ll see Chalier standing in front of some bones. You will have a choice of a spear, sword, or hammer when he offers you a weapon. Your selection doesn’t significantly impact the outcome. Once you make your choice, Chalier will then instruct you to meet him in a nearby building for a duel.
The Aftermath Decision
After you beat Chalier, he will ask you to kill him. If you do this you will raise morality. The option divides the quest into two distinct rewards.
If you Kill Chalier, you will obtain Auto Powerful Picto. This Picto will automatically apply the Powerful buff to your character for the first 3 turns of battle.
The Consequences of Mercy
If you choose to spare him, Chalier will express his disappointment and ask you to leave. When you return to the Floating Cemetery, you will find out that Chalier seems to have taken matters into his own hands in exchange for 11,680 Chroma.
Your mercy is worth more than this. After you meet Chalier, fly to the floating island called the Fountain near the Spring Meadows area to find Blanche.
If you have repeatedly taken the decision of not hurting Nevrons throughout your Quests, including Chalier, Blanche will gift you 100 Colour of Lumina for your goodness.
On the other hand, if you have killed any Nevrons that give quests, Blanche will become hostile. As a result, a tough battle on the level of an endgame battle would require characters of about level 80 to survive. If you defeat Blanche, you’ll get only 10 Colour of Lumina and 2 Grandiose Chroma Catalyst. Clearly, you get less than what you get from mercying.