Mike most likely stated that because it makes sense to give a unique more options when building within the tree. That being said, I believe Marine’s Lost Soul intention in the design process was to give players a way to scale possess damage (not ignite) because currently it’s a bit lack luster. I think there is value in keeping the unique to specifically cater to that playstyle if that is the design intent.
Regardless, we will bring this up internally and see how the team feels about this interaction.