When the first act in Clair Obscur: Expedition 33 ends, your characters begin their journey from Stone Wave Cliffs to the Forgotten Battlefields with their newest party member, Verso. The battlefields present a grim, unsettling environment, spoils of war, and their own set of collectibles. This guide covers the location of all of them and in a manner that is most efficient.
All Forgotten Battlefield Collectibles
Collectible #1: Polished Chroma Catalyst

Go past the Main Gate Flag until you reach a wooden walkway. Climb up and turn right to spot the collectible in a corner.
Collectible #2-3: Ramasson and Longer Shell Pictos

Proceed ahead from the last location and defeat the first enemy you encounter at the intersection.
Collectible #4: Troubadin

This item is dropped by another enemy, who roams near the last one.
Collectible #5: Energising Start IV Pictos

Go east from the intersection, into a cubby topped with wooden spikes.
Collectible #6: Colour of Lumina

This time, turn west from the intersection and follow the road until it ends.
Collectible #7: Colour of Lumina

From the intersection, you will notice another narrow path at the west end. Follow it until you spot a corpse and the collectible nearby.
Collectible #8: Recoat

Turn around and take the stairs up from the last location, where you will see the collectible hidden inside a crate in the ruins.
Collectible #9: Healing Tint Shard

This collectible is in the same ruins, near a sword buried in the ground.
Collectible #10: Sweet Kill Pictos

Go up to the cliff that looks like a junkyard from the last location, then turn right to spot the collectible.
Collectible #11: Revive Tint Shard

Return to the intersection, and go east until you come under a bridge. The collectible is lying near a tree.
Collectible #12: Colour of Lumina
From the Fort Ruins flag, go west and climb through some handholds. Enter the semi-arched gate, and you will spot the collectible on a stone platform.
Collectible #13: Colour of Lumina

Climb up the stairs to your right from the previous location, and go towards the corpse in the room to your right.
Collectible #14: Energising Death Pictos

In the same building as before, go to the next floor and circle around to see the collectible atop a ledge. You can even spot it from below.
Collectible #15: Polished Chroma Catalyst

You need to unlock the ability to destroy the blue spikes to get this collectible. It can be done by looking for four lost Gestrals. Outside the semi-arched gate, these spikes are blocking access to a room. Destroy them to find the collectible.
Collectible #16: Energy Tint Shard

From the Vanguard Point flag, climb down the cannon and break the boxes beside the huge pile of corpses, behind the large Gestral.
Collectible #17-19: Colour Lumina x5, Recoat, Polished Chroma Catalyst x5

From the Battlefield expedition flag, head west and defeat the escaping Petank.
Collectible #20: Colour of Lumina
This collectible is located just behind the Battlefield flag.
Collectible #21: Expedition 41 Journal

Turn around from the Battlefield flag and enter the trenches, then go left.
Collectible #22: Colour of Lumina

This collectible is just outside the chamber from the last location.
Collectible #23-26: Lusteson, Energising Parry Pictos, Colour of Lumina x5, Polished Chroma Catalyst x2
Head deeper into the trenches until you reach the Chromatic miniboss. Defeating him nets you the collectibles.
Collectible #27: Empowering Tint Pictos

Climb up the rope in the chamber next to the miniboss to spot the collectible.
Collectible #28: Chroma Elixir Shard

You must shoot three mechanisms to open the paint cage containing the collectible.
- The first one is up the entrance of the trenches, on the other side of the spiky log.
- The second is left of the entrance, behind some barrels and crates.
- The third one is the chamber adjacent to the location, again behind some boxes and barrels.
The paint cage is located near the last mechanism, and can be seen just as you enter.
Collectible #29: Expedition 57 Journal

This collectible is outside the Ancient Bridge flag.
Collectible #30: Inverted Affinity Pictos, Benisim, Polished Chroma Catalyst x5, Recoat, Colour of Lumina x3
Sold by the Gestral Kasumi, in the ruins near the Ancient Bridge flag.
Collectible #31: Obscur Outfit for Maelle
Fight and defeat Kasumi to unlock this outfit in his shop.
Collectible #32: Dualiso, Combo Attack Pictos, Polished Chroma Catalyst x3

These collectibles are obtained after defeating the story boss Dualliste.
Collectible #33: Colour of Lumina

Cross the bridge ahead after facing Dualliste, then climb up the small cliff to spot the hidden collectible behind a rock.
Collectible #34: Colour of Lumina

Continue on the same path until you reach a rope that takes you down. Climb down, then turn around to see a hole in the wall that you can crouch through.
Collectible #35: Revive Tint Energy Pictos

Follow the path opposite the last location up a hill.