2D pseudo edge light effect

Ok guys, I'm working on a pseudo edge lighting effect and I need some help.

I've got an arm sprite and a sprite that is just the edge light. I also have a stencil shader for the edge light.

https://imgur.com/a/sIi5F4I

The first question is, can you have a feathered sprite mask or stencil shader? Cause I as you can see in the picture, thee edge is too sharp to make a good lighting effect.

The second is, is there a way make only the closest edges (of the edge light sprite) to the "light source" show up in the stencil?

Thanks in advance!

Edit: It could also work if I had a lit shader for the edge light and the opacity is dependent on the amount of light hitting it.

 

Anyone know a solution to this?

I found this shader and it works, but the edge is to sharp. Any way to make the alpha based on the amount of light?

Spoiler: LightToAlpha

Code (CSharp):

1. Shader "Custom/LightToAlpha" {
2.     Properties {
3.         _Color ("Color", Color) = (1,1,1,1)
4.         _MainTex ("Albedo (RGB)", 2D) = "white" {}
5.         _Glossiness ("Smoothness", Range(0,1)) = 0.5
6.         _Metallic ("Metallic", Range(0,1)) = 0.0
7.         _ALightThreshold("Light Threshold", float) = 0.0
8.         _ALightContrast("Light Contrast", float) = 1.0
9.     }
10.     SubShader {
11.         Tags { "RenderType"="Transparent" "Queue"="Transparent" }
12.         LOD 200
13.  
14.         CGPROGRAM
15.         // Physically based Standard lighting model, and enable shadows on all light types
16.         #pragma surface surf Standard fullforwardshadows finalcolor:alphaLight alpha:fade
17.  
18.         // Use shader model 3.0 target, to get nicer looking lighting
19.         #pragma target 3.0
20.  
21.         sampler2D _MainTex;
22.  
23.         struct Input {
24.             float2 uv_MainTex;
25.         };
26.  
27.         half _Glossiness;
28.         half _Metallic;
29.         fixed4 _Color;
30.         half _ALightThreshold;
31.         half _ALightContrast;
32.  
33.         void surf (Input IN, inout SurfaceOutputStandard o) {
34.             // Albedo comes from a texture tinted by color
35.             fixed4 c = (fixed4)1.0f;
36.             o.Albedo = c.rgb;
37.             // Metallic and smoothness come from slider variables
38.             o.Metallic = _Metallic;
39.             o.Smoothness = _Glossiness;
40.             o.Alpha = c.a;
41.         }
42.  
43.         void alphaLight(Input IN, SurfaceOutputStandard o, inout fixed4 color)
44.         {
45.             fixed4 c = tex2D(_MainTex, IN.uv_MainTex) * _Color;
46.             color.a = 1.0f - saturate(c.a * saturate(dot(color.rgb, fixed3(1.0f, 1.0f, 1.0f) / 3.0f) - _ALightThreshold) * _ALightContrast);          
47.             color.rgb = c.rgb;
48.         }
49.  
50.         ENDCG
51.     }
52.     FallBack "Diffuse"
53. }