Indeed, and that is one of the several elements that captures the true essence of his character. To be honest, his voice acting in all the languages were very well done.
The English accent used by his voice actor (Luke Allen-Gale) is called the "Received Pronunciation"...also called the "RP" accent. Some people also call it "Queen's English" -- in reference to the Queen of England but there is a very subtle, almost unnnoticable difference. All in all, the RP accent is a very posh, deliberate, precise and clipped manner of English speaking... in the old days, it was --and still is in certain circles-- the traditionally aristocratic style of English speech.
Since we are on the subject of a character in a game, I shall give similar examples of other characters in games who speak with (or close to) the RP accent... off the topp of my head, Vayne Solidor of FFXII, Prince Maximillian of Valkyrie Chronicles... and if you haven't played those games, just think of Jeremy Iron's voice as Scar in Lion King.
I've mentioned this a few times on the forums and I'll say it again... Zenos is fourth generation imperial royalty and as such, his eloquence is not just required; its very likely demanded of him.
