Before you read this page, be sure you have read the "Getting Started" page on this wiki.
J'zahar, Gatekeeper of the Abyss is the 3rd boss of the game. His temple is in a village in Omothol located at X: 4 Y: 53 Z: 7. If you need to perform any rituals, head to X: 4 Y: 54 Z: 85 before anything else to do the rituals. Now go up the left or right stairs. To awaken J'zahar, Enter the room you see him sitting on his throne in on the second floor. The moment you do, He will awaken and start attacking you.
J'zahar is the most powerful boss in the game, yet not the last. Take down his minions he spawns in, and avoid shout attacks or blackholes. If you get sucked into a blackhole, you will be teleported to the Dark Realm. But be careful! Going at him with a sword is not a good idea! If you get too close to him, he'll instant kill you! The best way to take him down is using a Coralium Longbow with infinity or more on it. J'zahar has 500 HP and 44 Armour points. When you beat him, he will drop an Essence of the Gatekeeper, which gives you access to the Abyssalnomicon (The book J'zahar holds). The Abyssalnomicon is the knowledge of All 4 Necronomicons together, and a little more. If you want to respawn him, perform the Ritual of Reversed Time at X: 4 Y: 54 Z: 85.
The dark realm dimension is entirely optional, but its where Sacthoth, Harbinger of Doom spawns.To get to the dark realm, your gonna have to use J'zahars Staff to create a portal, or just get sucked into a blackhole.