Layton was a secretive agent of the Mages Guild, who sought to right the issues regarding the magical wards of Kinoclast.
With the Peas helping him, he was able to redirect the harmful magic built up in Azmok's Tower and push it outwards, effectively covering half of the world in hopes that at that point the magic would be spread too thin to hurt anyone.
In messing with some of Azmok's magics, Layton ended up disfigured, with his arm notably turned into a large tentacle.
Layton told the party that he worked out of Madrioc, and to ask for him if they ever went there.