Who or what decides that someone has enlightened himself? Who or what decides that someone has enlightened himself?

It's just about an urge to know the point where/how enlightened one's or their followers approve that 'they are enlightened'. What happens immediately after that?
Only you can decide for yourself that you are truly enlightened.

Why: Because enlightenment is overcoming any and all ideals and dogma you impose upon yourself, including the need for enlightenment.