The NPC called Dryleaf Dane has a secret side quest in Elden Ring Shadow of the Erdtree DLC. This walkthrough shows the full solution. Completing this quest unlocks the Dryleaf Arts (weapon) & Dane’s Hat.
Missable Warning: This quest must be completed before burning the Sealing Tree at Church of the Bud (Point of No Return). Most NPCs and their questlines become unavailable after this point.
Walkthrough
Step 1: Pick up the “May The Best Win” gesture at Highroad Cross site of grace. It’s directly at the site of grace.
Step 2: Go to Moorth Ruins, slightly east of where you found the gesture. Dryleaf Dane stands at the site of grace there, but he won’t talk to you. What you have to do is perform the “May The Best Win” gesture in front of him. This will trigger a duel against Dane. Defeat him. To perform gesture open the menu > scroll to the right side where it says “Gestures” > click “Switch” > choose the gesture and click “Test now”.
After the fight you get a short loading screen. Next to the Moorth Ruins site of grace, Dane will have dropped your reward: Dryleaf Arts (weapon) & Dane’s Hat.
This finishes Dryleaf Dane’s quest, the shortest of all NPC questlines in the DLC.
For all other NPC questlines refer to Elden Ring Shadow of the Erdtree – All Side Quests.