The main hazard is Damage Walls. There will be multiple Damage Walls up at the same time so bring all Null Damage Wall monsters. This dungeon is a No Heart dungeon with no Healing Walls. You need Recovery monsters to keep your HP topped off. . On the first turn, Wyatt Earp does a DEF Up on herself. Use that time to clear mobs to mitigate damage. Wyatt Earp is a Demihume Slayer. Do not bring Demihume monsters like Saizo and Red-Hood Nonno. However, you can bring D'Artagnyan as she dish out more damage than she takes.