Poison
Not many had seen the battle between Third Nova and Second Nova. It could even be said that the latter had wanted it this way. He attacked right when it seemed that Third Nova was about to enter a state of slow expansion.
After watching the Heir Wars for many days already, the novelty had worn off and many were entirely focused on whichever region had the most action. As such, quite a few had no idea who had even injured Second Nova to begin with, even the Morales Ancestors were quite clueless.
Since poison was used, the immediate assumption was the Pyius family, and Auran and Kira did nothing to refute this. For whatever reason, they didn't want to describe what had happened and maybe that was always the plan.
Despite Kira's crying, Auran couldn't seem to hear or feel anything but a spine tingling pain. He looked up toward the starry skies, his lips pressed into a line. Maybe he had never thought that things would end like this.