Wizz Air, the dominant ULCC in Eastern Europe, is adding Varna flights from Gatwick for the summer season. This is in addition to its existing service from London Luton. Varna is a popular Black Sea getaway and Bulgaria generally represents good value for tourists.

https://simpleflying.com/new-summer-route-londons-wizz-air-adds-direct-flight-to-bulgaria/

It's interesting that if this route had existed in the past, Count Dracula could have avoided his fraught journey to the UK on the Demeter.