Underground Labyrinth · Stage 21Underground B21F地底21層Data updated: 2026-07-2430Energy Cost1,692XP Reward350,000Enemy Base HP5,200Stage Length5Max Enemies8.3Difficulty Build a lineup for this stage Test your team vs this stageStage rewards50% — XP ×200,000 · Treasure RadarEnemy spawns (5)EnemyStrengthCountFirst SpawnRespawnBase HP TriggerNotesDoge Dark600%∞13.3s16.7s~23.3s100%—Dark Otter100%123.3s—100%—Doge Dark600%353.3s30s100%—Dark Otter100%166.7s—100%—Shadow Boxer K200%186.7s—100%—All Underground Labyrinth: The Grand Deep stages