So, I won't answer the first question since I read the korean chapter and I know how the situation will unfold.
As regards the second question, I tried to find some kind of clue, and I can tell you that in the korean version of ch 51, the bad guys who are chasing after Diesel and his father yell "DEMON" in english and not korean.
From this I made some assuption:
1)Diesel and his father are in a state where people speak english
2)Diesel and his father are escaping from people who speaks english
If we assume for a moment that Diesel's homeland is in Siberia and we consider the first option as true, it's likely he and his father are in Alaska. Infact, Alaska is separated from Siberia by "only" the Beiring Streit. Furthermore English is the most-spoken language in Alaska.
Another detail which supports the first option is the landscape: in the first panel author drew some tree and even if they have few detail they might the "Betula papyrifera" (also known as "paper birch") which is a short-lived species of birch native to northern North America. (Notice that birch is tree widespread in the Northern Hemisphere, only paper birch is tipically found in northen North America, at least Wikipedia says so!)
I didn't even consider the second option since I didn't find enough clue to formulate a theory and english is known by many people all over the world.
Now the question is why Diesel and his father are escaping?what's there in Diesel's past that is so dangerous to reveal that Yanek warned him to not tell his real name to anyone?
While the author revealed Bexan and Pablo's breed, he/she didn't explain what kind of dog Diesel is....I'm starting to believe Diesel might be the long lost prince of a likely dog fairyland.
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Where did you find the Korean chapters? (⊙…⊙ )
Is this when Ein kills Yanek, accidentally or with purpose? And where were Diesel and papa...in Siberia??? Wooof!