Overlay difuse shader (Object Above Everything else)

DiffuseOverlay.shader

Shader "Custom/DiffuseOverlay" {
Properties {
    _Color ("Main Color", Color) = (1,1,1,1)
    _MainTex ("Base (RGB)", 2D) = "white" {}
}
SubShader {
    // Tags {"RenderType"="Opaque"} // original
    Tags {"Queue" = "Overlay" "RenderType"="Opaque"} // modified
    ZTest Always // this line is added
    LOD 200
 
CGPROGRAM
#pragma surface surf Lambert
 
sampler2D _MainTex;
fixed4 _Color;
 
struct Input {
    float2 uv_MainTex;
};
 
void surf (Input IN, inout SurfaceOutput o) {
    fixed4 c = tex2D(_MainTex, IN.uv_MainTex) * _Color;
    o.Albedo = c.rgb;
    o.Alpha = c.a;
}
ENDCG
}
 
Fallback "VertexLit"
}