Nah, it's vladiSLAV (forgot the "s"). The only Polish Tsar (& the only puppet, frankly only non-russian). Interesting history, to read up on in wikipedia and a nice video on HistoryMarche channel on youtube "Battle of Klushino"
Great quiz. My only suggestion is to allow the Russian versions of the names (Paul/Pavel, Alexander/Aleksandr, Nicholas/Nikolai, etc.). After all, you have Ivan and Feodor instead of John and Theodore!
Sophia served only as regent while Vladislav was technically elected Tsar (de jure), though his reign was brief and he was never crowned (hope this answers your question)
Can you accept Vladyslav for Vladislav? I’ve seen the “y” version a lot, and it’s in one of my history books. He was the only guy I missed because it didn’t accept the “y” spelling.
Also, I would add Semiboyarshchina(Seven boyars). They ruled in 1610-1612 before Michael Fedorovich began to reign, and their leader was Mstislavsky.