Clive was Clavell's original name. Clavall is an alias.
Clive was originally part of the research team for Area Zero, Turo being his apprentice.
Knowing that a potential spill out could happen on the isle, Kalos sent him to the university to essentially train a group of student operatives to send down into Zero.
Them being children paramount as the Legendary down there has the power to materialize thoughts.
By eventually utilizing Florian, Arven, Nemona and Penny, Clive is able to wrap up the Area Zero mess before spilling into the Kalos mainland, neighbor of Paldea.
The concept of "Finding your treasure" is both an exercise in exploration (locating Area Zero) and imbuing the children with an ideal so that the Legendary in Area Zero would not corrupt their wish.
