Both, depending on which sounds better in the sentence.
I pronounce it “The Romanovs deserved it”
i’m interested in how the mis-chee-vee-us pronunciation came about, considering the word isn’t spelled mischievious. is it a regional thing that has spread over time or is it something else?
I did a super-quick google…
Mischievous Definition & Meaning - Merriam-Webster
Mischievous vs. Mischievious: Usage Guide
A pronunciation \mis-ˈchē-vē-əs\ and a consequent spelling mischievious are of long standing: evidence for the spelling goes back to the 16th century. Our pronunciation files contain modern attestations ranging from dialect speakers to Herbert Hoover. But both the pronunciation and the spelling are still considered nonstandard.
probably similar to how restaurateur doesn’t have an n in it, yet a lot of people still pronounce it (myself included)
miss-ch-viss