Are we really writing about Hitler Semen? No, Semen Hitler. Actually...
Semyon Gitler is probably the better spelling. Transliteration!
The Hitler... fine, Gitler in question is a Ukrainian Jewish soldier who fought in World War II. This Gitler was quite a hero, gunning down hundreds of Nazis. He perished in 1942 in the Siege of Sevastopol, barely at the age of 20. But, you know, Hitler! We mean Gitler!
So let's explain the wonders of transliteration. The first name, "Semen", is just a Slavic version of "Simon", but has a pesky "ё" as the second vowel. The two dots are often omitted, but, you know, "semen". Since that version of the "e" sounds like "yo", the better transliteration is "Semyon". Beats "Semen", we give you that.
As for the last name, because Russian lacks the soft "H", most names that start with an H get transliterated with a "G". So Harry Potter in Russian is... Garry Potter. (In Ukrainian, it's a soft "G", but let's not confuse ourselves any further.) This turns Adolf Hitler into Adolf Gitler, which makes his name sort of equal to our Semyon Gitler, but not really.
One of the stories is that the Germans discovered Semyon's family and decided not to exterminate them... who knows, right? What if they were long-lost relatives... Stupid Nazis!