LaValle explained to both Drizzt Do'Urden and Artemis Entreri that his loyalty was first and foremost to the organization itself, not to a particular leader, so he served loyally someone that cared about the guild. He had no more ambition, and considering that he survived longer than most members of Calimport's criminal networks this seemed a good strategy.
LaValle was a lieutenant in Pasha Pook's guild for a long time and knew Artemis Entreri very well.
Under the orders of his boss, he was involved in fighting with the Companions of the Hall searching for Regis. Thank to his powerful magical artifact, the Taros Hoop, LaValle sent the heroes to the plane of Tarterus. To his great surprise, Drizzt Do'Urden and his friends came back, smashing the Taros Loop in the process. LaValle surrendered.
Later, LaValle became a lieutenant of the new guildmaster, Regis.
Some years later, Artemis again met LaValle, now a lieutenant of a new guildmaster. LaValle told Enteri that his new boss was a good man.