Question

What makes the Indra's vajra invincible

Answer 1

Answer:

This asura was the recipient of a boon which made him invulnerable to any known weapon. ... Vishnu revealed to Indra that only weapons made from the thunder-containing (called in Sanskrit as Vajra) diamond bones of the sage Dadhichi could kill Vritra

Hope it helps you

Thank you❤❤❤❤❤❤