[Discussion]About modifying lol

I am kinda curious where all the important datas(maps,characters,skills etc) are stored in, other than notepad files. I used to modify dll and make ijl in Mabinogi. But i am not sure where Lol has the important data. Im not even sure lol is all server-sided or not.
Recently i though of an idea where you swap effects for nocturne so that blindness goes away.(since it's like Data blind effect activates->your screen is blind but if you swap. Data blind effect activates->nothing happens since the file doesn't include anything like that just visual)

Think of the client like a constant interactive stream.
visuals are all that the client needs.

yeah if your files aren't exactly the same as the wat the client is looking for the game crashes or else crashes when nocturne ults. this is excluding skins and particles.