A type of mantra, a relatively long one is called a dharani.
A dharani is a spell that is believed to have mystical power and is the essence of the Buddha's teachings, and is said to help one remember the teachings and not forget them, as well as to give one an excellent memory and many good deeds.
In this way, Dharani Bodhisattva continues to preach the Buddha's teachings, profound meanings, and ultimate truths to all living beings.
It is said that twenty-five bodhisattvas accompany Amida Buddha when he arrives, and he is one of the bodhisattvas who protect practitioners who wish to live in the eternal life.