Similarly, Indra is also a manifestation of Lord Rudra. AtharvaVeda calls Rudra as slayer of Vritta which is actually Indra:
“sahasrākṣáu vr̥trahánā huveháṃ dūrégavyūtī stuvánn my ugráu |
yā́v asyéśathe dvipádo yáu cátuṣpadas táu no muñcatam áṃhasaḥ ||” (Atharvaveda 4:28:03)
“The thousand-eyed slayers of Vritra both do I invoke. I go praising the two strong gods (ugrau) whose pastures extend far. Ye who rule all these two-footed and four-footed creatures [Pasupati], deliver us from grief and trouble”.
YajurVeda which states everything like fire, water, air, sun, moon, etc... gained their characteristics features because Lord Shiva manifested as Ashtamurti Rupa ie. He entered in all those 8 things as Purusha and made them active. Satapatha Brahmana of YajurVeda from 22.214.171.124 to 126.96.36.199 states:
Rudra is Agni.
Sarva is Water (Varuna).
Pasupati is Plants (Vanaspati).
Ugra is Air (Vayu).
Asani is Lightening.
Bhava is Raingod (Parjanya).
Mahadeva is Moon (Chandra/Soma/Mind).
Ishana is Sun (Surya/ Atman)
Thus, it is clear the whole world is pervaded by the forms of Lord Rudra. So as Rudra is actually Agni, Vayu, Varuna, Soma, Surya, etc.. as seen from above Shruti passage (of YajurVeda). So actually Vedic hymns to all these Gods are actually praying various forms and manifestations of Lord Rudra.
According to Rig Veda 2:33:03:
“śreṣṭho jātasya rudra śriyāsi tavastamastavasāṃ vajrabāho |
parṣi ṇaḥ pāramaṃhasaḥ svasti viśvā abhītī rapaso yuyodhi ||” (Rig Veda 2:33:03)
“In beauty thou art the most beautiful of all that exists, O Rudra, the strongest of the strong, thou wielder of the thunderbolt! Carry us happily to the other shore of our anguish, and ward off all assaults of mischief”.
I have read about Rudra being described as vajrabaahu(holder of thunderbolt), asani (lightening or vidyut) or meghapati (master of clouds). How can this be briefly explained?