Brotato - Road to Wave 1000! - 57th Attempt Reached Wave 50 Using Demon

So I saw this video of someone who played using Demon who reached Wave 1000 so I'm trying to do the same. It's not as easy as it seems to be, still trying the pattern for the build but this is the farthest that I reached so far. XD
If you have any tips, feel free to comment!
Enjoy!