Descendents of Prince Felix Yousoupoff
If we discard Pavlov's obsolete law of succession, which was abolished in 1917 , a potential successor to the throne of the Russian Empire will emerge.
He should be ruled in accordance with the current trends in monarchic law:
1. abolition of the division of marriages into dynastic and morganatic.
2. Equali rights for the male and female line of succession, while preserving the right of primogeniture.
In connection with the termination of the line of succession of Nicholas II, it is necessary to go back to the descendants of Alexander III.
Then the line will look like this:
Alexander the Third gave birth to Xenia. Fourth child. Elder brothers Alexander and George have not left posterity. The line of Nicholas the Second is finished.
Ksenia Aleksandrovna Romanova (March 25 (April 6), 1875, Saint Petersburg - April 20, 1960, Windsor, UK) was the Grand Duchess, daughter of the Emperor Alexander III. She was the sister of the last Emperor Nikolai II. On July 25 (August 6) 1894 she married Grand Duke Alexander Mikhailovich, the grandson of Nicholas I.
They had 7 children, the eldest of which was the daughter Irina.
Irina Alexandrovna Romanova (3 July 1895, Peterhof - 26 February 1970, Paris) was a princess of the imperial blood, in marriage Princess Yusupova Countess Sumarokov-Elston.
The couple had one daughter, Irina Felixovna Yusupova, born in St Petersburg on 21st March 1915. (Princess Irina Felixovna Yussupova, (21 March 1915, Saint Petersburg, Russia - 30 August 1983, Cormeilles, France), married Count Nikolai Dmitrievich Sheremetev (28 October 1904, Moscow, Russia - 5 February 1979, Paris, France).
Thank you, Al_bina! 
