In western Cysael, enter the wrecked house next to the Cysael West portal. There is a trapdoor hidden by a rug. Go downstairs to find a sarcophagus. Drag the lid off of it to release Snorri. Talk to him, and he will give you a challenge to destroy a blue orb within a time limit. Fail his challenge, and Snorri will break it himself. Destroy Snorri's ball outside of the time limit to get the "Wrecking Ball" achievement.