The Cursemark of Death is a very important key item for players that want to get the Duskborn Ending in Elden Ring. It is not an easy item to obtain, either, as it requires getting far into Ranni's quest. Her questline requires killing some very difficult Elden Ring bosses and exploring some of the more dangerous locations of the Lands Between.
The Cursemark of Death is on top of the Divine Tower of Liurnia, which is east of the Artist's Shack. The tower requires an item, though, to make it to the top. The player will need the Carian Inverted Statue, and that is only obtainable through Ranni's questline.
Elden Ring: How to Get Into Renna's Rise
The player must first pick up the questline at Renna's Rise, which is past Caria Manor in Liurnia. This will require defeating the boss, Royal Knight Loretta.
Once Ranni's Rise is accessible, the Tarnished can speak with her and begin her questline. The player will have the option to speak with Blaidd at Siofra River, or they can skip that part and go straight to Radahn (though some lore and character interactions will be missed).
What is not optional is to fight and defeat Starscourge Radahn. Once that is completed, a new area will open up in Limgrave. A crater will appear west of Fort Haight that leads down to Nokron.
Once down there, seek the Fingerslaying Blade. To get to it, the Tarnished will have to beat the Mimic Tear Boss. The Fingerslaying Blade will be found in a big chest north of the Night's Sacred Ground Site of Grace. Note that a lot of Mimic Tears will be patrolling this area.
Once the Fingerslaying Blade is obtained, give it to Ranni back at Renna's Rise. She will then reward the Tarnished with the Carian Inverted Statue. Her quest is not yet done, but with the Carian
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