How to make an aura around a character

In Blender 4.1, I’m trying to make an animation based off of JJBA, and wanted to try making the “aura” that the characters have when using their abilities, how could I do this in the Eevee engine? I tried looking up tutorials, but they didn’t seem to work.
Aura ref

Try using Layer Weight Node.

From Blender 4.2 (EEVEE_Next), you should use the Glare node in Compositing to give a diffused light effect.

Maybe it can help, you can make an outline
Maybe you can mix outline technique with an upward cloth simulation(reverse gravity)