Bersimon, also known as the Weather Wizard, is a rabibunny that lives in a tent located in the Wizards Lane, on the upper part of Citadel Island. He graduated from the School of Magic, and keeps a diploma of Elementary-Weather Magic, with a rank of Grand Master of sea winds and tornadoes. He tries to make a Ring of Lightning and needs a Pearl of Incandescence.
He intends to clear the storm above the Island but he can't find Raph the Lighthouse keeper anywhere. When Twinsen finds him, Bersimon is outside Twinsen's House and "informs" him of the news, and together go there and he performs his spell. This allows the Esmers to land.