I’m quite sure this has happened to me a few times since last update. A hero in defence has just released a special attack and the mana bar is still filled halfway. I specifically notice it happen with Hel but also think it has happened when playing against lianna. Anyone else that has noticed this or am I only dreaming? It might be in combination with blind.
Edit: after tests and also input in thread below it is confirmed that when heroes miss special attacks because of low accuracy they will retain a outback half their mana. It is so far not confirmed if this is intended feature or bug.
@Petri has confirmed in thread below that this is an intended feature of lowered accuracy.