It's pronounced like a Z. (zEYE-con) There's a joke about it in one of the comics where someone says Zykon in the speech bubble. Another character points it out, and the first character can't work out how they could tell the difference. (I can't remember exactly who says it. It might be in SoD.)
Hey, that's pretty cool. It's not exactly the same, but considering how the art style has developed since then, it's similar enough.
Similar sound effect aswell. <checks SoD> And same again with Lirian's Gate.