One Russian Culture
This is a very simple mod which removes the Novgorodian and Ryazanian cultures from the game and replaces them with Muscovite, which is renamed Russian. Should work with localizations.
Did you just conquer Russia and want to accept hundreds-of-dev-worth of land with one culture slot? Do you favor accuracy over game balance? Or are you a Russification maniac who wants the beautiful word “Russian” to cover the whole world? If your answer to any of these is “yes”, then this mod is for you.