Fragment/Vertex shader complex issue

The shader below is Slin's planet shader, which I've reversed normals on because he had them facing away from lights instead of towards.

The shader works great on static objects and in the scene viewer, but when I apply the shader to a rotating planet, the effect rotates with the mesh instead of staying based on light direction/position and camera position/dircetion.

I want the effect to stay in place when the planet is rotating but the camera isn't.

Also, was wondering how to combine this with a BlinnPhong based specular, normal, and parallax shader to make a single shader. Applying 2 materials causes artifacts.

If they can't be combined into a single shader file, how can I make this shader texture-less?

     Pass
     {
         Name "AtmosphereBase"
         Tags {"LightMode" = "Always"}
         Cull Front
         Blend SrcAlpha One
        
         CGPROGRAM
             #pragma vertex vert
             #pragma fragment frag
            
             #pragma fragmentoption ARB_fog_exp2
             #pragma fragmentoption ARB_precision_hint_fastest
            
             #include "UnityCG.cginc"
            
             uniform float4 _Color;
             uniform float4 _AtmoColor;
             uniform float _Size;
             uniform float _Falloff;
             uniform float _Transparency;
            
             struct v2f
             {
                 float4 pos : SV_POSITION;
                 float3 normal : TEXCOORD0;
                 float3 worldvertpos : TEXCOORD1;
             };

             v2f vert(appdata_base v)
             {
                 v2f o;
                
                 v.vertex.xyz += v.normal*_Size;
                 o.pos = mul (UNITY_MATRIX_MVP, v.vertex);
                 o.normal = v.normal;
                 o.worldvertpos = mul(_Object2World, v.vertex);
                
                 return o;
             }
           
             float4 frag(v2f i) : COLOR
             {
                 i.normal = normalize(i.normal);
                 float3 viewdir = normalize(i.worldvertpos-_WorldSpaceCameraPos);
                
                 float4 color = _AtmoColor;
                 color.a = pow(saturate(dot(viewdir, i.normal)), _Falloff);
                 color.a *= _Transparency*_Color*dot(-normalize(i.worldvertpos-_WorldSpaceLightPos0), i.normal);
                 return color;
             }
         ENDCG
     }