Arben's Sword is a quest item you can get rid of in the slayer camp, if you have a certain quest from the dragon cliff castle.
The second keg of explosives can be used shortly after the where the first one was needed. There is a blocked passage off to the right.
^^^
The quest involving Arben's Sword is 'Down the Hatch" where you have to trade it for the "Chalice of the Dragon"
I chose to not trade and go for the experience the fight would give so I had my creature and my undead(8 points) already summoned whch made the ensuing fight easier.
I never needed or found the second blocked passage to use them so I am looking for something to blow up.
Kel******