Caser
@RUSProspects
Many Russian names have diminutives that are for use by relatives and friends only e.g. Vladimir becomes Volodya, Viktor becomes Vika, Aleksandr becomes Sasha, Mikhail becomes Misha.
EDIT: Since you bring up Rexxar, LS, I think interestingly that there is a diminutive for bears that is similar. Masha? Perhaps geoo9 or kshadoo will help me remember.
In Russian fairytales a bear is always being named Mikhail for some reason, so the bear diminutive is Misha too.