Male names:
Rostyslav means “growth and glory.”
Ruslan is a very popular name in the former Russian Empire. It derives from Tatar name Uruslan and the possible Turkic root arslan (lion).
Ruvym is the Ukrainian form of Hebrew name Reuven (Behold, a son). A rarer form is Ruvim.
Female names:
Rehina is the Ukrainian and Belarusian form of Regina (queen).
Romaniya is a feminine form of Roman name Romanius, ultimately derived from Romanus (i.e., Roman).
Ruslana is the feminine form of Ruslan.
Onomastics Outside the Box 
The C.S. Lewis fans would probably pick up on Aslan and Ruslan being related.
And the Tatars loved their Us.
Thank you for Rehina too.
Does Rostyslav have a nickname the way the other -slav names do?
Pingback: A to Z Reflections 2022 | Onomastics Outside the Box