The boss has three health bars — it transforms after each one is depleted.
Tips
register
Pure gaming term. Use 血条 for the on-screen bar; 血量 (xuèliàng) for the HP value itself. Common verbs: 掉血 (diào xuè, lose HP), 回血 (huí xuè, regenerate), 满血 (mǎn xuè, full HP). The 血 ('blood') feels more vivid than English 'health'.