NieR: Automata's 3C3C1D119440927 DLC unlocks three challenging Colosseums. After receiving the Mysterious Letter, you'll need to locate these arenas to reap their rewards. Each Colosseum features six ranks of progressively difficult enemies, culminating in unique Rank S rewards.
Colosseum Locations:
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 the colosseum's entrance. A machine guards the entrance, but it poses no significant threat.
- Rank S Reward: Destroyer Outfit (A2)
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 to the right. Circle around the left side of the building to find a Resistance member guarding the entrance. Bribe him with 1,000 G to enter.
- Rank S Reward: Revealing Outfit (2B)
Underground Colosseum
Accessible only while 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 the locations for all three colosseums within the 3C3C1D119440927 DLC. Good luck conquering these challenges!