A grand demon descended on the planet named Mahishasura. He was a grand one in the terms of ego. He performed deep penance and pleased Brahma Ji. He asked Brahma Ji to bless him with a boon of immortality and strength. Brahma Ji said that he could not make him immortal. Mahishasura asked him to make him invincible before demigods, demons, and mortals. Brahma Ji granted the boon.
Mahishasura began exploiting the three worlds. All the inhabitants began fleeing in stress. They pleaded to Lord to free them from the pangs. Lord closed His subtle eyes, a magnificent ball of light descended on the land of mortals. The ball took a form of a beautiful young lady. She moved towards the court of Mahishasura. Seeing a young beauty, he was attracted to her and proposed to her for marrying him. The lady smiled, nodded, and suggested that she would prefer fighting before accepting the groom. The results of the battle would decide fate. Mahishasura giggled, spurting a devilish look. The war began.
The war went on for nine days. She played a magnificent play and fought as a naive goblet of innocence, for the eight days. On the ninth day, She took the form of Kali and pierced the demonic form inside out.

Mahishasura symbolizes the ego. We consider the false self as the supreme authority, even stronger than Lord. Only the Lord, Mahishasura Mardini can abolish the ego. Chanting and surrendering are important.
One day, a Guru granted Diksha to His shishya. The shishya asked about the Guru Dakshina he could present. Guru asked him to present the most useless asset of the planet. He moved outside and lifted a handful of clay. The clay yelled that it was the source of nutrition for all the creatures. He left the mud and picked up a stone. The stone shouted that it was the same idol that is worth being placed on the altar. Shishya was puzzled. He sat down for a while and thought that his mind was the source of all confusion. He went to his Guru and offered his mind at His divine feet. And, Lo! He was freed.
We do not have the capabilities to abolish the ego, but we can portray the flow of thoughts in the right direction. And, one day, the ego will disappear.