In some Buddhist denominations, The Twelve Yakṣa Generals or Twelve Heavenly Generals are the protective deities, or Yakṣa, of Bhaiṣajyaguru also known as Medicine Buddha, the buddha of healing. They are introduced in the Bhaiṣajyaguruvaidūryaprabharāja Sūtra also commonly known as Medicine Buddha Sūtra.
In sūtras it is said that by reciting Amitābha’s name, will one to be reborn in his Western Paradise the Land of Ultimate Bliss. But for others who become severely ill and have affinity with Bhaiṣajyaguru or the Medicine Buddha as he is often referred to, reciting his name while you are still alive, will help you recover and come to higher spiritual realization, to suffer less and will also help prepare you to be reborn in either Buddha realms of your choice, either Medicine Buddha’s Eastern realm of Vaiḍūrya Light or Amitābha Western realm of Sukhāvatī.
Medicine Buddha on achieving Buddhahood, became the Buddha of the Eastern pure land of Vaiḍūryanirbhāsa “Pure Lapis Lazuli”. There, he is attended to by two bodhisattvas symbolizing the light of the sun and the light of the moon respectively. Their names are:
1. Suryaprabha Bodhisattva (Sunlight)
Translated Vietnamese name: Nhật Quang Biến Chiếu Bồ Tát
2. Candraprabha Bodhisattva (Moonlight)
Translated Vietnamese name: Nguyệt Quang Biến Chiếu Bồ Tát