User blog comment:SpiritedDreaming/RWBY: Attack on Kevin Tower Defense Game/@comment-27803627-20160830172224/@comment-26018514-20160830215455

no, he only loses 100HP once a month, he heals HP daily... meaning he gets 100 HP in 10 days minimum if all 10 species are left, if we get to the point we can hurt him already... well without this he should already die, but with this he creates approximately 3-4 hp generators, so he generates 5 hp per day that reduces as we kill them off, starting with the Beringel, which means we likely have at least one species naturally respawn again, keeping him steadily regenerating and only extending his life about a week.

Should it be completely in his favor? no, it's about making things interesting at the point we would otherwise only be targeting him.