This is a little script that converts your text into faux Cyrillic characters by replacing some Latin characters with Cyrillic characters that look similar.
While the resulting text is linguistic nonsense, this technique is sometimes used in books, movies, and video games to evoke a Russian or Soviet feel while conveying a message in English (or another language).
Here's an example:
THЗ GЭИЗЯДTФЯ ЬLФG
[ Fake Cyrillic Text ]