If you take Stabbing Blast (recall sends blades towards enemies) and Nightmare Dash (recall when using Shift instead of Umbral Blades), using Shift does not send blades towards enemies but instead simply deletes any blades currently on the ground.
Discovered this when trying to use Bladestorm Umbral Blades being left being by shadows, but appears to still be bugged with only these two nodes spec’d together.