Is my Boss Fight Too powerful for Roblox to handle?

I am building an obby game that has a special boss fight at the end but for some reason the script only works once per server, if another player is to enter the boss fight after someone else, half of the script doesn't work. Also scripts for other parts of the obby stop working, for example simple kill brick scripts.

My script is too big for this website :/

I have but my script on this pastebin instead:

RobloxBossFight - https://pastebin.com/xjwTcLBQ

any tips on how to reduce lag and scripts breaking will be very much appreciated.

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