DROP:
Extremely Rare NPC drop or base crate drop, or limited mission item.
Single use.
Upon use, the next randomised drop, either from a base crate or elite NPC, will bring up a box where you may select what drops from it. For example, if used with a Lvl4 base crate, you could choose 20 CTP, 40CTP or the tri-phase.

One would only wish but this will be abused

i've been thinking of suggesting a drop distribution priority system...

on locking an elite or boss npc, you'd be allowed to prioritize which drops you'd prefer...

the drops would still be randomly handed out normally, then everyone that didn't get their #1 preferred drop would get their drop lists analyzed and randomly switched for their highest priority drops if possible... that way it would make the most people happy
(been holding off on the suggestion because of the headaches involved coding a system like that)