NieR: Automata's 3C3C1D119440927 DLC unlocks three challenging Colosseums. After receiving the Mysterious Letter, you'll need to locate these arenas to earn unique rewards. Each Colosseum features six ranks of progressively difficult enemies.

Colosseum Locations:

1. Trial of the Sand Colosseum:

Located in the desert. From the "Desert: Center" access point, look to the right (facing the desert entrance) for an orange diamond marking its location. A machine guards the entrance, but poses no significant threat.

• Rank S Reward: Destroyer Outfit (A2)

2. Gambler's Colosseum:

Found in the Flooded City. Begin at the "Flooded City: Coast" access point. Follow the path towards the coast (the same route used to protect the resource ship). At the end, locate a waterfall. Circle around the building to the left of the waterfall; a Resistance member guards the entrance. Bribe them with 1,000 G to enter.

• Rank S Reward: Revealing Outfit (2B)

3. Underground Colosseum:

• 9S Only: This Colosseum is accessible only when playing as 9S.

Start at the "Forest Zone: Center" access point. Follow the left edge of the forest until you find machines training near a large waterfall. Pass through the waterfall to access the Colosseum.

• Rank S Reward: Young Man's Outfit (9S)

This guide provides concise directions to each Colosseum, enabling efficient completion of the DLC content. Remember to achieve Rank S in each to claim the exclusive outfits.