In a combat with wolves to the east of Foelmar in Magran's Fork, I used Aloth to cast Necrotic Lance. He starts the casting animation and then does nothing. There is no travel or damage animation. The combat log does not show that he cast the spell or that any damage was done.

Interestingly, the travel animation and damage went out in the next wolf's turn. It appeared that actions were actually overlapping. My cipher PC had used Whispers of Treason to control one wolf. I've noticed that charmed enemies seem to behave oddly. For example, if the last enemy alive is charmed, then the normal turns will continue, but the enemy just delays for like 5s before doing nothing and allowing the turn to proceed.