Kumbhakarna, the younger brother of the Demon King Ravana was basically a Satvik[Pure] person who went astray due to the malefic influence of Ravana, Kumbhakarna possessed such great strength that no warrior could stand before him, he is said to have annihilated entire armies of powerful soldiers. Even Hanuman failed to defeat Kumbhakarna and ultimately Shri Ram killed him
The Kumbhakarana Mantra for Possessing Great Strength given below should be chanted 1000 times using a Rudraksha Japa Mala. This is said to give the practitioner Mastery over the Mantra. Before commencing the Mantra chanting the practitioner should bring a mental image of Kumbhakarna in his mind and while chanting the Mantra imagine the immense power and strength is entering his body.
ॐ अहो कुम्भकर्ण महा राक्षस निकषा गर्भ आज्ञापय स्वाहा ||
Om Aaho Kumbhakarna Maha Rakshasa Nikasha Garbha Aaagyapaya Swaha ||
Then while going for a fight, the practitioner should take a White Cotton Thread, hold it in his right hand, and chant the Mantra 108 times to infuse the White Thread with the power and potency of the Kumbhakarna Invocation Shabar Mantra. Then he should tie the Mantra Infused White Thread like a Protective Talisman on his right upper arm.
Note- the Mantra Experiment was used in the Early and Late Middle Ages by soldiers going for a war. I am not in a position to vouch for the success of this Mantra Experiment to gain unsurpassed strength, as I have not seen this Mantra being tested by any person in an actual fight or war.
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