Devonshire is the leader of the Rogues' Guild. For how long? Well, quite a while. No one can ever remember him not being around.
Chex the Cubone showed up rather recently--before Mission 1-- on a task. What task? Devonshire still isn't sure because Chex is a mute. Chex will sometimes write out what he wants on a card, but it's not often. He's fine this way, as well.
Devonshire is pretty sure Chex came from a graveyard of some sort. Chex is always carting around a little wagon full of bones he's collected. He makes frequent trips out of Tao Village, likely to the graveyard to deposit bones.
Devonshire's unusual fondness for this Cubone has been noted by Gunpowder (who wisely says nothing).