Answer in Details
In the Shiva Purana and other Shaiva scriptures, Shiva is described as omnipotent, omniscient, and omnipresent. He is considered the source of all power (Shakti) and the cosmic consciousness that pervades everything. The concept of Shiva as the most powerful is also illustrated in stories where even other gods, including Vishnu and Brahma, seek his grace and blessings.
However, in Hinduism, the supremacy of deities can vary according to different traditions (Shaivism, Vaishnavism, Shaktism). In Shaivism, Shiva is supreme; in Vaishnavism, Vishnu holds that place. But for devotees of Lord Shiva, he is indeed the most powerful god, representing the ultimate and infinite consciousness.