This is true. Many are unworthy to serve in the fight against our enemies. [Only the rare few can survive the process of becoming a Space Marine, after all. Everyone else is just...weak. Confirmed.]

You have completed your duty there? [Maybe he's envious. To have fulfilled one's duty is the highest honor. ]

They must store them somewhere. [And if he figures out where all he'll need is a huge derelict Astartes warship to aim at it. Solved. ] It would gall me to have to perform as some entertainment for these foul creatures of Chaos.