What to do with the Deathroot in Elden Ring

gamepur.com:

As you explore Elden Ring’s setting of The Lands Between, you might come across a key item known as the Deathroot. As is often the case with FromSoftware games, it’s not exactly clear how you use this rare item. However, giving the Deathroot to the right NPC can allow you to get some pretty useful items.

Upon obtaining the Deathroot, you’ll have to talk to D, Hunter of the Dead. D can be found on the road east of Summonwater Village. If you’ve spoken to him and unlocked the Roundtable Hold, then D will be present in the hub area. Talk to him, and you’ll receive a prompt to show him the Deathroot. He’ll then suggest you take it to Gurranq, a Beast Clergyman who craves Deathroot. D will mark a Sending Gate on your map, which will allow you to access the Bestial Sanctum, where Gurranq resides. The Sending Gate is northwest of the Third Church of Marika.

After interacting with the gate, you’ll teleport to an area featuring a set of double doors. Head through the doors and you’ll see Gurranq in the back of the room. Simply interact with him using the Y/Triangle button to hand over your Deathroot, and Gurranq will reward you with various Beast items. Any additional Deathroot you find can be fed to Gurranq to obtain more items.