I am working toward completing the Harbinger Title. Outside of a flawless Master Hunt and 2 more Master Time trials i still need to get a drop of the 'Bane of Crota Shell' I have been playing since 2019 and i checked that i have defeated the final tier v boss 111 times over the 4 year period with no drop in sight. When, may i ask, do we come to the point where the drop for the shell becomes guaranteed?