Lord Indra degraded - Part - I

Sri Rama, after killing demon Viradha ,enters the hermitage of Sage Sharabhanga. Sri Rama has seen Indra, the lord of three worlds, with a radiant body mounted on a great chariot that does not touch the earth and yoked with green horses, at the Sage Sharabhanga’s ashrama.

विभ्राजमानम् वपुषा सूर्य वैश्वानर प्रभम् |
रथ प्रवरम् आरूढम् आकाशे विबुध अनुगम् || 

असंस्पृशन्तम् वसुधाम् ददर्श विबुध ईश्वरम् |
संप्रभ आभरणम् देवम् विरजो अंबर धारिणम् ||
तत् विधैः एव बहुभिर् पूज्यमानम् महात्मभिः |

"Rama has seen Indra, the Lord of three worlds, with a radiant body that has the coupled radiance of Sun and Fire, mounted on a great chariot that does not touch the earth, wearing greatly brilliant ornaments and attired in spotless dress, while the other divinities are attending, and many more selfsame great-souls are worshipping him."

हरितैः वाजिभिर् युक्तम् अंतरिक्ष गतम् रथम् ||
ददर्श अदूरतः तस्य तरुण आदित्य संनिभम् |
पाण्डुर अभ्र घन प्रख्यम् चन्द्र मण्डल संनिभम् ||

"Rama saw at his very nearby a chariot yoked with green horses that traverses in firmament, which in its splendour is either like the noontime sun, or a cluster of silver clouds, or like the silvern sphere of the moon."

अपश्यत् विमलम् छत्रम् चित्र माल्य उपशोभितम् |
चामर व्यजने च अग्र्ये रुक्म दण्डे महाधने ||
गृहीते वर नारीभ्याम् धूयमाने च मूर्धनि |

"He saw the stainless parasol of Indra, marvellously garlanded and shining forth, and the exemplary and invaluable royal fanning instruments with golden handles, which two best female celestials are handling and fanning at Indra's head sides with them."

गन्धर्व अमर सिद्धाः च बहवः परम ऋषयः ||
अन्तरिक्ष गतम् देवम् गीर्भिर् अग्र्याभिर् ऐडियन् |

.

And the celestials like gandharva-s, amara-s, siddhaa-s and very many great sages as well are extolling Indra, who is abiding in firmament.

On seeing Indra speaking there to sage Sharabhanga, Rama spoke to Lakshmana.  

ये हयाः पुरु हूतस्य पुरा शक्रस्य नः श्रुताः |
अन्तरिक्ष गता दिव्याः ते इमे हरयो ध्रुवम् || 

"Of which horses we have earlier heard from our teachers telling that they belong to Indra (शक्रस्य), the Chief Invitee in Vedic rituals (पुरु हूतस्य), they are these divinely green horses that now abide in the firmament, and definitely these must be Indra's horses."

इमे च पुरुष व्याघ्र ये तिष्ठन्ति अभितः दिशम् |
शतम् शतम् कुण्डलिनो युवानः खड्ग पाणयः || 

 विस्तीर्ण विपुल उरस्काः परिघायत बाहवः |
शोणांशु वसनाः सर्वे व्याघ्र इव दुरासदाः ||
उरो देशेषु सर्वेषाम् हारा ज्वलन संनिभाः |
रूपम् बिभ्रति सौमित्रे पंच विंशति वार्षिकम् ||

"And oh, manly-tiger Lakshmana, those that are there in hundreds and hundreds around Indra, those youthful ones with their ear-ornaments and swords in hands, with wide and broad chests, with club shaped arms, and clad in glimmering red garments, all are like tigers, all are unapproachable, all of them are wearing ornamental chains on their chest-place that are akin to flaring fires, and in their appearance, Soumitri, they always bear a look of twenty-five-year-olds"

एतद्धि किल देवानाम् वयो भवति नित्यदा |
यथा इमे पुरुष व्याघ्रा दृश्यन्ते प्रिय दर्शनाः || (Aranya Kanda 5 Sarga 5 - 18 Slokas)

"The age factor of gods remains constant at the age that appears for these nice-looking Tigerly-men, so they say... for gods are immortals and they will be ever young.

 Sri Rama proceeded towards the hermitage of Sage Sharabhanga to know clearly about the resplendent one on that divine chariot. On seeing Sri Rama arriving there, Indra bade farewell to Sage Sharabhanga and travelled to heavens by the chariot.

In Ramayana, Lord Indra was eulogised only next to Lord Brahma, as much importance was not given either to Vishnu or Shiva. It is evident from the words used (पुरु हूतस्य  - Chief Invitee, [in rituals]) in the Slokas.  Śakra (शक्र) means The  mighty-one.  He was a boon giver and Lord of 3 worlds.