Seeing the battered and beaten appearance of the Lightning draconic Serpent, Simon panicked and his brain immediately went into overdrive trying to think of some ways to salvage the situation.
If the Lightning draconic serpent was beaten here, it would be subdued by the orc general which means that he wouldn't be able to keep his words with Aldebaran. He had to subdue the three overlords of the north and bring them under his rule within a year. If even one of them was missing, it wouldn't be seen as him keeping his words.
All this while he had been thinking that he wouldn't even have to step into this battle since he believed that the orcs were no match for the Lightning draconic Serpent. However, surpassing his expectations, the orc army, especially the orc general was able to overwhelm the overlord of the north and bring it down.