I'm talking about both singular and plural form of "you", so I hope the provided answer will include both answers.
You are the one who 《are/is》...
I'm equating the "singular you" with the "singular one" and both words have different conjugation of "to be" i.e. are and is respectively, I suppose. I believe I would choose is in this case. So it would be:
 You are the one who is ...
However, I'm not sure since I believe this construction sentence below is correct (don't ask me why because I don't know the reason, it just makes sense to me):
I see you who are sweeping the floor right now.
My point is, I'm not sure whether the conjugation has to agree with "the one" or "you" or either way is correct I don't know.
You are (all) the 《one/ones》who 《is/are》...
My guess about the correct writing is like this:
 You are (all) the ones who are ...
Are my guesses  and  above correct grammatically? Is there another possible combination I haven't mentioned which is correct? If this doesn't make sense to you, could you please suggest another construction to avoid confusion as to either singular or plural form of "you" which I want to address?
Thanks in advance!