Is there any way to replicate After effect's lightning?

Snadegg

Hello, I'm trying to learn as much as I can, but I'm still a beginner so please bear with me, but  I'm trying to replicate the lightning in After effects (I'm adapting this video: ), or more specifically, the "alpha obstacle" setting ( I know that I could draw a small mask at the edge I want, and go from there, but it doesn't interact quite the same. The After effects setting stretches the lightning when it's at an angle, while the technique I had in mind does not. If you have any ideas, it would be greatly appreciated.

Thank you in advance.