something spawning in a specific proximity range

i have a boss in my game jimmy boss and for phase 3 i want it that shades spawn inside of its proximity heres the link click on the type named jimmy bossflowlab.io/game/view/1398105

i forgot the link i just edited the original post

I dont see a boss fight or phase 3 in the game.
And what you mean by proximity isn’t the behavior but a place in the game.

For using a specific area on a game, find the with and length of the area you want (like from 32 to 384), then set those numbers in 2 randoms (X & Y) and that will randomly pick a spot inside that area.