Can exploiters change value inside their character?
Example:
Inside exploiter’s character he can see his values, if he try to change value by this script, value will be changed on his client or on client and server?
Exploit changes are client sided. The only way they can affect the server is through vulnerabilities on the developer’s side, or if the properties they change are replicated.
The only way this can be a problem is if you’re using client-sided values to make purchases (which is something you shouldn’t be doing in the first place)