Zarhym teleports you to the Spirit World after you speak with him. In the Spirit World, Zarhym follows you around and tells bad jokes while you are chased by Timeless Spirits. When you find Zarhym's Body, loot it to receive a reward for your trouble and the achievement Zarhym Altogether.
Additionally, Zarhym (the CM it is named after) has confirmed that this is a reference to comedian Mitch Hedberg's 2005 album "Mitch All Together"
https://twitter.com/CM_Zarhym/status/377903669595090945
Zarhym teleports you to the Spirit World after you speak with him. In the Spirit World, Zarhym follows you around and tells bad jokes while you are chased by Timeless Spirits. When you find Zarhym's Body, loot it to receive a reward for your trouble and the achievement Zarhym Altogether.
After finding Zarhym's Body, you will automatically complete the weekly quest "Tom" Bone Apart - Tracking Quest and will not be able to see Zarhym again until weekly quests reset.