I know that I will write a bad advise right now for you, but just because my husband is a foreigner and I checked all the possible rules for migrants in Ukraine... really we are open just for the foreign students for a studying period when university will help with legal reason to be in Ukraine, and for those who have spouse or child with Ukrainian citizenship.

For all the others Ukraine is good because nobody will ask your documents until you will decide to leave Ukraine and pay the fine on passport control. And still 3 months later you will be welcomed again :)