Valmiki Ramayana Yuddha Kanda Sarga 51 Shloka 14
Original Shlokaतच्छ्रुत्वावचनंतेषांराक्षसेन्द्रोमहाबलः । चिन्तारोषसमाक्रान्तोविषण्णवदनोऽभवत् ।।6.51.14।।
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महाबलः of mighty prowess, राक्षसेन्द्रः Rakshasa king, तेषाम् by that, तत् वचनम् those words, श्रुत्वा hearing, चिन्तारोषसमाक्रान्तः very worried and enraged, विषण्णवदनः pale face, अभवत् remained.
The Rakshasa king endowed with mighty prowess became pale in face, worried and enraged on hearing the words of Rakshasas.