https://godotshaders.com/shader/glow-effect-2d/ I found this shader. Is it the effect you want?
subtle yoke
https://godotshaders.com/shader/glow-effect-2d/ I found this shader. Is it the effect you want?
subtle yoke
Hmm, I am not experienced enough in shaders to help you with that one.
sonic edge
That's odd, most effects of that kind increase the intensity when in the middle of the view, could you have applied the math wrongly somwhere?