Shiva the mighty God.

In india there are so many cults in Hindu religion, and the oldest we see is the Shiva and Shakti.
Shiva is usually worshipped in the abstract form of Shiva linga. In images, he is generally represented as immersed in deep meditation or dancing the Tandava upon Maya, the demon of ignorance in his manifestation of Nataraja, the lord of the dance.

As per my knowledge the most powerful is Shiva cult. why this become more powerful? No one have the precise answer for this.Let me know your views.

Depiction of the Hindu god Shiva as the cosmic dancer who performs his divine dance to destroy a weary universe and make preparations for god Brahma to start the process of creation. Nataraja is most often depicted through a statue.

The sculpture depicts, with Shiva dancing in an aureole of flames, lifting his left leg (and in rare cases, the right leg) and balancing over a demon or dwarf (Apasmara) who symbolizes ignorance. It is a well known sculptural symbol in India and popularly used as a symbol of Indian culture.

The two most common forms of Shiva's dance are the Lasya (the gentle form of dance), associated with the creation of the world, and the Tandava (the violent and dangerous dance), associated with the destruction of weary worldviews - weary perspectives & lifestyles. In essence, the Lasya and the Tandava are just two aspects of Shiva's nature; for he destroys in order to create, tearing down to build again.