[Tristan Lall]

While I understand that "thunder" doesn't translate very well into imagery, you're depicting lightning (two different ways). That's not the most straightforward branding.

It will look fine in print, but won't on a t-shirt or banner (the fine detail will look like bad printing).

Consider doing a vector (e.g. .svg) version, or at least make sure that you keep the details in separate layers in a raster version.