- Glorified in Vedas, Agamas, Upanishads, Mahabharata, Shivarahasya, 10 out of 18 Mahapuranas, 10 out of 18 Upapuranas. The largest Purana, Skanda Purana is dedicated to him.
- Defeated all the devas combined together. None ever (other than Krishna & Arjuna and some asuras with boons) has defeated all the devas combined together.
- Defeated the most powerful entity of the creation in the form of Lord Vishnu at least four times (Daksha yagna episode, Sharabheshwara leela, Vrishabeshwara leela, Yaksheshwara leela) if not more.
- Only entity ever known who destroyed Lord Vishnu's personal armour which was embedded upon demon Sankhachuda.
- Only entity ever known who defeated Arjuna (a portion of Lord Vishnu).
- The deity who drank the Kalakuta poison.
- Only entity ever known who stopped the Sudarshana chakra other than Ravana. As Bhadra (or in some versions Kshetrapala) in Daksha yagna episode. As Hanuman in front of Lord Krishna's palace.
- Perhaps the only entity who was worshipped in all ages and by all.
- An entity who is the chief divinity of all indigenous mythologies throughout the planet, starting from Batara Guru in Indonesian mythology to Maheshwara in Indian mythology (I prefer the word mythology rather than Itihasa since it sounds better). It signifies his lingam (phallic emblem) has been worshipped throughout all ages.
- He can grant immortality if pleased. He has granted immortality to many notable of his devotees, namely, Nandi, Bhringi (Andhaka), Parashurama, Shweta (as per Linga Purana), Markandeya (as per South Indian Shaivism texts), Upamanyu, Banasura, Surya, and Ashwatthama (as per Shiva Purana).
- He is himself immortal being the master of Yama, the presiding deity of death.
- He saved his devotee Shweta from the clutches of Yama as mentioned in Skanda Purana. Only Lord Krishna other than him has ever achieved the feat of bringing back his own devotee (Sandipani's son) from Yamaloka. An impossible feat otherwise.
- He was the entity for whom even Lord Krishna abandoned the Kurukshetra war and visited Kailasha for paying a lifetime tribute.
- As per umpteen instances in Mahabharata, Lord Krishna has worshipped him in many forms in millions of aeons throughout time in various incarnations, since incarnations of Narayana are multiple, much more than just ten.
- He was the only entity who was in reality worshipped by Lord Krishna, rather than just paying tribute. Also he is the only one who is worshipped by Lord Vishnu (original form of Lord Krishna) at any time, place, or position.
- Included in the Trinity of Brahma, Vishnu, and Shiva, which forms of basis of the supreme trio in all religious dogmas within the Hindu Sanatana dominion.
- He was worshipped by Lord Rama as mentioned in Ramcharitamanas, Narasimha Purana, Kamba Ramayana, and many popular versions of Ramayana, including being mentioned in Valmiki's version after the war while Lord Rama was returning from Lanka in Pushpaka vimana.
- The only entity who ever defeated Balarama (the direct manifestation and first expansion of Lord Krishna) and rendered him inactive in battle. The instance of Shiva Jvara , the cold fever. Balarama's defeat by Shiva Jvara is mentioned in Harivamsa, Vishnu Purana, Agni Purana, and Brahma Purana.
- One of the largest denominations of Sanatan dharma concerns his worship as the supreme deity, known as Shaivism.
- He is the consort of Parvati, the most popular Hindu goddess of them all (regardless of various religious sects) who has killed the most number of demons. He himself has killed crores of demons even some of them who has defeated Lord Vishnu. Some notable demons killed by him includes Jalandhara, Andhaka, Apasmara, Gajasura, Tripura, and Sankhachuda.
This answer is based upon these texts of Sanatan dharma including texts of Southeast Asian Shaivism :
- Mahabharata
- Harivamsa
- Shiva Purana
- Skanda Purana
- Linga Purana
- Vamana Purana
- Kurma Purana
- Vayu Purana
- Agni Purana
- Padma Purana
- Vishnu Purana
- Varuna Purana
- Ribhu Gita
- Ishwara Gita
- Javanese Saivism
- Pitutur Agung Sang Batara Guru
An illustration of Shiva destroying Tripura (the three invincible demon citadels) below for your interest.
Image courtesy : Google search