Syndelius is quite curious and questionable. He will inspect and be cautious of all the traps in the chambers of Xedilian.
Sheogorath sent the Hero to Xedilian to attune the Resonator of Judgement in A Better Mousetrap. Once this task is completed, this next quest begins and the Hero must choose traps for the adventurers to fall in.
He will either die or go insane in the second chamber depending on the player's actions.