God damn. Looks like dialogue with deaf man.
There ARE official russian rules of transliteration. Bunch of them. Link to wiki was given above. 'kh' is used for 'х' in more than 50% of them.
At first it looked like you didn't read. Now it looks like you canot keep in mind relevant memories. There are different 'х' sounds. For some reason russian translators often get 'kh' as base for our 'х'. 'kh' is not russian invention.