Outpost In The Woods - Act 4 Side Quest

Start Location: Ixian Woods
Quest Location: Ixian Woods/Den of the Anteok
Objective: Defeat Surryln the Belligerent in Den of the Anteok

Outpost In The Woods is a quest given to you by Chrysis, a scout who runs over to you immediately after entering Ixian Woods. Once you've accepted the quest from him report to Teisias, the Sergeant to the northwest of where you met the scout. He'll currently be under attack by enemies, save him and talk to him to update your quest.

After updating your quest you'll need to head to the northeastern cave in this area, Den of the Anteok. The location is shown in my map screenshot below. Inside of this cave you'll find Surryln the Belligerent whom you'll need to defeat to update your quest. Return to Teisias to turn the quest and claim your reward with Surryln dead.