Complex sentence: A visitor arrives and Count Waldner is surprised to see that it is not his friend Mandryka; however, the man who enters who turns out to be the friend's nephew, also named Mandryka.
Split into simpler sentences: A visitor arrives and Count Waldner is surprised to see that it is not his friend Mandryka. However, the man who enters turns out to be the friend's nephew, also named Mandryka.