If you say that something is happening or will happen for good or ill, you mean that it is out of anyone's control whether it happens and what its effects will be.
[formal]
The world, for good or ill, had moved on.
See full dictionary entry for ill
Examples of 'for good or ill' in a sentence
for good or ill
The question is whether it will be for good or ill.
Times, Sunday Times (2008)
You know with him that something will always happen, for good or ill.
The Sun (2011)
Strictly is often a catalyst in people 's lives - for good or ill.
Times, Sunday Times (2008)
For good or ill, it will be a long time before the law of the land is enticed back into the impenetrable world of horse racing.