This is a real Russian alphabet, which systematically destroyed, first by the Greeks Cyril and Methodius, and then by Peter the Great and then the Bolsheviks from 49 to 33 letters.
OLD RUSSIAN, Русский шрифт
Uncial is a majuscule script (written entirely in capital letters) commonly used from the 4th to 8th centuries AD by Latin and Greek scribes.
Фонетическое прочтение древних буквиц
Old Slavic Manuscript ~ The Four Gospel from Benchevo dating from the beginning of the 16th century.
Greek alphabet calligraphy how to. Fine Arts by Claudio Saes: Three Faiths Exhibition at NY Public Library
Miloš Ćirić, Sava's face, uppercase, (reproduction of the only sample from unfinished book)