The final Legacy Dungeon in "Elden Ring: Shadow of the Erdtree" is Enir-Ilim. This dungeon is accessible after you progress through the game's storyline, specifically after dealing with the events at Belurat, Tower Settlement, and defeating the boss Romina, Saint of the Bud. Here's a bit more context based on general gameplay mechanics and player progression:
Location and Access
Enir-Ilim is located to the northwest of Belurat, Tower Settlement, but it becomes accessible only after significant progression in the DLC, specifically after defeating Romina, Saint of the Bud in Rauh Ruins. After this encounter, players need to burn the sealing tree found in the area post-boss fight with Messmer's Kindling, which leads you directly into Enir-Ilim.
Structure and Exploration
•Layout: Enir-Ilim is complex, featuring verticality, interconnected paths, and hidden routes, much like other legacy dungeons in the game. This dungeon encourages exploration, with multiple levels of rooftops, courtyards, and interior chambers to navigate through.
Key Areas:
•Start Point: After burning the tree, players find themselves on a balcony, from where they can explore downwards into various rooms, finding sites like the First Rise and Spiral Rise Sites of Grace.
•Navigational Challenges: Players will need to use lifts, jump across gaps, and explore both indoors and outdoors, encountering various enemies and secrets.
•Bosses: While Enir-Ilim doesn't have a traditional boss at the start, players encounter various tough enemies like the Erdtree Shaman and eventually lead up to the final confrontation of the DLC.
Bosses
The primary final boss of the "Shadow of the Erdtree" DLC, which players face towards the end of Enir-Ilim, has been noted for its difficulty. The feedback on X (formerly known as Twitter) suggests this boss might be challenging due to visibility issues during the fight, potentially leading to a community expectation of a nerf.
Items and Loot
Revered Spirit Ashes and Scadutree Fragments are among the notable items found here, crucial for enhancing player capabilities. Unique Incantations like Spira can be found, adding to the game's magical arsenal.
Community Sentiment
Players have praised Enir-Ilim for its aesthetic design, complexity, and the sense of finality it brings to the DLC's narrative. However, some have critiqued the difficulty curve of the final boss, suggesting it might be overly challenging.
Gameplay Tips 
•Explore Thoroughly: Enir-Ilim is designed to reward exploration. Hidden paths, branches, and rooftops often lead to valuable items or strategic shortcuts.
•Use Grace Points: Grace points like First Rise and Spiral Rise are crucial for resting, respawning, and planning your next moves in this labyrinthine area.
•Prepare for Boss Fights: With feedback indicating the final boss might be particularly tough, coming prepared with the right gear, spells, and possibly co-op partners could be beneficial.
Conclusion
Remember, Legacy Dungeons in "Elden Ring" are pivotal for both gameplay progression and experiencing the depth of the game's lore. Enir-Ilim, being the final one in the expansion, would logically encapsulate all these elements, providing both a mechanical and narrative climax to the Shadow of the Erdtree storyline.
