Give me your opinions or ideas about a character's aura,for eg,

1. Aura is of truly unique matter that doesn't exists

2. This aura is powers granting aura

3. It is visible only to the user

4. For anyone attacks on the user,the aura works as shield which when touches anything that is coming to hame the user,it simply erases it

5. Aura is truly deadly looking

I need ideas pls suggest me!

Also,I need a sound of aura too except from dragon ball series,mob psycho!