First, for the melee ability, Vanish in Smoke, I would add the effect “[i]increases sprint speed and enhances the radar for you or your allies when they are invisible[/i].” This keeps the idea as an escape tool and adds some utility to the ability from the enhanced radar part.
The Lockdown ability does not need to be touched as I think it is already good on its own.
Second, for the third ability, Heart of the Pack, I would keep the part where you generate orbs on killing tethered enemies as that is already really good. What I would change is instead of increasing mobility, recovery, and resilience on killing tethered enemies, I would instead do this “[i]killing tethered enemies will also grant you and nearby allies an over shield[/i].”
I would actually not change Moebius Quiver itself. Instead I would to rework the Shadowshot super itself. What I would do is instead of pressing L1R1/LBRB and it being cast and shot immediately, you would press the button/s to cast your super but then you will go back to being in first person and aim it like any other bow in the game. This will affect both bottom tree as well as top tree nightstalker as it would turn into a rooming super. I fell like this would give more control to the player as to where they actually want to shoot the tether.
If you like my idea then be sure to give this a thumbs up so the Bungie can see this.