Kazu's probably going to be adventuring until he's too old to safely pick up a glaive, which leaves his two options as death or retirement. I don't have any specific plans to give him an untimely demiwe, but it's not like it's out of the question in his line of work. If he makes it to retirement, though, I see him becoming a storyteller and chronicler of fables that's always foisting unsolicited advice to young adventurers. That's the clearest image I have for him, so I suppose it's also the most likely.
All credit for the graphic to Benedict Whiteraven, you magnificent bastard.