Why does `ChargeTime` go up rapidly if I spam Q?

Try to think of what lines is being executed, one step at a time:

1. The script initializes
2. You press down Q. 'debounce' is now true so the loop starts. It goes through your code until it hits the `wait(1)`.
3. You let go of Q, let's say after 0.2 seconds. 'debounce' is now false.
4. Let's say that 0.3 seconds after that, you press down Q again. Now, InputBegan is going to start again (on a new `coroutine`), set 'debounce' to true, and it's going to start up a new `while` loop. Like before, it goes through your code until it hits `wait(1)`. Notably, since `ChargeTime` is not local to the function, it is shared between coroutines (which is fine), which is why ChargeTime will now be 2.
5. Let's say you hold down Q now for a full second. Before that second is up, the first coroutine (started on step #2) is going to resume and check to see if it should continue the loop. It sees that 'debounce' is true and so keeps going! It increase ChargeTime to 3. At the end of the second, the second coroutine (started on step #4) will do the same thing, increasing ChargeTime to 4. By the time you've let go of Q, ChargeTime is at 4 and it's only been 1.5 seconds total.

Clearly, spamming Q can make this effect even more dramatic.

The problem is that you are trying to use debounce as a keyDown variable. debounce is specifically for preventing a function from executing the code 2+ times at once and is set up like this:

local debounce = false
function Example()
	if debounce then return end
	debounce = true
	--code here
	debounce = false
end

Change your debounce variable's name to keyDown and then add proper debounce to make sure that you won't run your while loop more than once at a time. Specifically, make sure to do the if debounce then return end before the while loop starts (and make sure to set debounce = true after the if debounce then return end and also before the while loop). Make sure that debounce will always eventually be set to true after it's been set to false, or else your script will stop running that section entirely. ex, this would be bad:

local debounce = false
function Example()
	if debounce then return end
	debounce = true
	print("HI")
	wait(1)
	if someCondition then
		print("Leaving early")
		return -- <------ this is bad; it returns without setting debounce back to false!
	end
	for i = 1, 10 do print(i) wait() end
	debounce = false
end