The 流体入侵怪 is a 困难模式, post-拜月教邪教徒 敌怪 that spawns near and is summoned by the 星尘柱 during the 月亮事件. When it spawns, three smaller minions will appear one at a time and begin orbiting it. The Flow Invader utilizes these as attacks, sending them as 1-2 high-speed projectiles towards the player. When it dies, it will shoot 3 projectiles as a final attack. The orbiting minions will reappear over time.