All these -slav and -mir names are just very dated and considered too uncool to be used now in Croatia. They're like
Bill or
Dick to English speakers. However I do like to see them used, especially by a non-Slavic speaker.
My favorite spelling is Svatoslav, that extra letter just jabs at my eyes. Svatoslav
Alexei is wonderful!
Vladimir Ilya -I like both names, but they just don't go well together, imo. There are just too many 'i' in the combo.
Vasiliy Berislav -I love it!
How about these:
Svatoslav Ognjen
Svatoslav
Dmitar
Vasiliy BranimirVasiliy KresimirVasiliy Tomislav