Ruthenia

Ruthenia is a country and character from Alternate Future of the World - Season 1. They were created when Novorossiya declared independence from Ukraine in 2018/2019, and nationalist rebels rose up in Ukraine to form a stronger government, which would later be known as Ruthenia.

In the second episode, Ruthenia joined the Vienna Pact upon its formation, and allied with Greater Austria. Since then they haven't made a move, but it's likely they have ambitions to retake Novorossiya, and Crimea from Russia. This leads to the possibility of a Vienna Pact-CSTO war.