I found a few that have potential:
Blazh m Medieval Slavic
Medieval Slavic name derived from Slavic blagu meaning "good, blessed, happy".
Borisu Борисъ m Medieval Slavic
Medieval Slavic form of Boris, probably ultimately of Bulgar Turkic origin. (BORIS- a Bulgar Turkic name, also recorded as Bogoris, perhaps meaning "short" or "wolf" or "snow leopard")
Dobrogost m Polish (Rare), Medieval Slavic
Derived from the Slavic elements dobru "good" and gosti "guest".
Gostislav m Medieval Slavic
Derived from the Slavic elements gosti "guest" and slava "glory".
Milivoj m Croatian, Serbian, Slovene, Medieval Slavic
Derived from the Slavic elements milu "gracious" and voji "soldier".
Radomil Радомил m Czech, Medieval Slavic
Derived from the Slavic elements rad "happy, willing" and milu "gracious, dear".