And when the sword pierced through the skull of the last demon soldier that was crawling on the ground in an attempt to get away, it signified the end of the battle. His Undead utterly destroyed the demon army that was fighting against his Undead Scourge.
This was a great victory and a great feeling that Samiel had from the victory over the Demon Army. While indeed, he used a great deal of subterfuge to achieve victory and not just pure military might, for Samiel, nothing was forbidden as long as it led to victory.
In contrast, in the Teleryan Pass, most of the demons that were fighting against each other in their maddened state killed each other, and if not, then in their weakened state, the curses that were inflicted upon them were enough to finish the job.