Hanuman assumed Panchamukhi or five-faced form to kill Ahiravana, a powerful rakshasa black-magician and practitioner on the dim arts over the Ramayana war. Ahiravana, brother of Ravana, had taken Lord Rama and Lakshmana to netherworld as captive, and the one way to kill him was to extinguish 5 lamps burning https://garrettyqbly.get-blogging.com/37341962/about-mantra