I don't play Dark Souls (and have only watched the first one played, once)...which one is being pointed to? (I do know they're called Ornstein and Smough, I just don't know which is which.)

I can imagine them both being mispronounced based on the English-language spellings (Ornsteen and Smog (or smohg) respectively)...and would mispronounce Smough, myself, without the kana version in front of me.

If it's Ornstein, I'd find it a bit maddening, too. In 99.9% of cases, 'ei' is pronounced 'I', not 'E', why assume this is an exception? (I'm looking at you, Simon Whistler. v_v)