Don't know must it be JASS but... Event: Hero reaches level X action: An dialog menu apears where you can choose next hero. After choosing a new hero apeares at position of old one. All items comes from old hero to new. EXAMPLE: -Riffleman / footman \ -Knight
Well, it'll be better in JASS of course I said i'm going to to that for you and i'll ceep my promise. It's almost ready now, just some bugs to remove and i'll post it