A Brother in Need Series

Death to the Dead:

After Conrad gives the reward for A Brother in Need he will be available to give this quest:

Go South to this location:

Enter the cave:

Where the blue dot on the map is you will find a group of unique Pirates:

They are lead by a Demon Lord, be careful of the poison spikes he casts:

If Conrad dies the quest will fail, but sometimes if you kill the entire group quickly enough (before his body disappears) it will change to completed and he will still reward you: