I know many Diavel/XDiavel fan expect V4 model. If V4 model would be released, I guess XDiavel would come up prior to Diavel. Because XDiavel was revealed autumn 2015 as Model Year 2016 and has almost stayed unchanged so far. But both Diavel and XDiavel are not popular generally. I think V4 model unlikely comes up. So if V4 model comes, it is unexpectid happening, threfore Episode 1: The Unexpected.