Ooookay... In that case, why not just call him "Below." You know, in English. They could call Kamina "Abovena," too. That way the English speaking audience will experience the irony just as the creators intended it. Genius!
After all, we can't all bust out our pocket Jappo lexicons, so casual viewers won't be in on the joke anyway. It would just be awkward and unnecessary.
tl;dr: His name is going to be pronounced like the name would be commonly pronounced in English. Same with Viral. Save the nihon purist bullshit for the trivia section in wikipedia.