This is a very hard effect to pull off convincingly, triply so in VR.
What I’d suggest is starting with a mesh like @Spyro did in his Supercell example:
Then, on that mesh you add cloud/Smoke textures. To get the internal lighting, you need to either paint it into the textures or bake it if you have it all set up in a sim. (A simulation like that is beyond my skill so I can’t help you I’m afraid).
Then you add some particles on top of this moving in a vortex to break the shape up.
Again, you need to keep it simle and cheap if you want it to run in VR.