The Shadowlands are accessible upon death, where the player-character can roam, and can only be seen by other spirits. The Spirit of Tony Two-Tusk describes the Shadowlands as all grey and dark, swirling clouds. While Uuna was in the Shadowlands, she described it as dark and she was unable to see anything, though she could hear people interacting with her in the physical world. From within the Shadowlands, she could see the light of the naaru A'dal who was in the physical world, but it was so bright that it scared her. The moonlight at Lake Falathim allowed her to see a friend in the physical world.
Explore the Realm of the Dead: for the first time ever in World of Warcraft, players will cross into the Shadowlands and experience the wonders and horrors of the afterlife across five new zones—the gleaming fields of Bastion, the scarred battlefields of Maldraxxus, the eternal twilight of Ardenweald, the opulent keeps of Revendreth, and the horrific Maw.
Shadowy Tormentors inhabit this dimension, and emerge from it to torment death knights such as Koltira Deathweaver. The Lich King originally kept them at bay, but after the Knights of the Ebon Blade left his service, the tormentors are now loose upon them. He even appears in the World of the Dead, as he calls it, riding a frost wyrm during  The Power to Destroy.
Unlike World of Warcraft’s other endgame dungeon activity, Mythic+ dungeons, Torghast is not timed. Instead, you have a limited number of lives before your run comes to an end. Once you’ve died a certain number of times, a giant, unkillable boss called the Tarragrue will spawn at the entrance to your current floor, and will slowly lumber toward the exit. If the Tarragrue spots you, it’ll chase you down and kill you in a single strike. But if you can reach the end of the current floor before the Tarragrue does, you’ll escape to the next floor.
Blizzard said last week that Torghast was inspired by roguelikes — games like Hades and Dead Cells, where each failed run rewards you with knowledge and skill that aid in your next attempt. Unlike a traditional World of Warcraft dungeon, Torghast has fixed levels with procedurally generated enemy spawns. The floors start simple, and eventually evolve into elaborate wings with traps, locked doors, and puzzles.
Sometimes, the spirits roam the Shadowlands without resting. It can be because their resting place wasn't complete, because of a battle in their resting place or because of the corruption of their resting place. To bring eternal peace to the souls, it is needed to destroy the source of corruption or by making a ceremony with items such as [Tuskarr Ritual Object]. A spirit in the Shadowlands can, with enough power over other souls, tear a hole into the living world once they are strong enough. This is how Jin'do returned to Azeroth.