Title sort of says it all:
If you could replace any one ability with something else that could benefit the hero/comps/game what would it be and why?
For mine I would replace Ana’s sleep dart with a monifilament tether.
Sight a target with a cursor (same as zen’s orbs). Hit the target with a projectile (same as the sleep dart is now). Target becomes tethered to a nearby object or surface (floor would probably be the easiest) and can only move in a 5 meter radius around the tethered spot.
This would Provide Ana with a stronger escape mechanism without adding further mobility to her kit. The tether would act like Junk’s trap and make movement abilities impossible to use.