As for the Dagger of Death, it had mixed-use to Darius. When he first acquired the dagger, its preciousness had been unmatched, for he could have used it to insta-kill someone greatly above his level and jump straight through the many stages to instantly reach the highest possible level... at least in theory.
At the time, he had been apprehensive of whatever failsafe Vena and Caesar had put in place, so he had not dared to act on his plans, rather slowly leveling himself up after he set up a social foundation in Listo.
Looking back, it had proven to be a wise choice borne from caution. Since it was now an established fact that he would be locked at the peak of his stage until he fulfilled whatever diabolical Quest the sadistic AI would come up with, not to mention his exp gain had been capped, the Dagger of Death had basically turned into a last resort item in case he needed to kill a big bad entity many levels above him.
