And how does Calyx even know about not only the reflections, but how did he know that his reflection is the 9th? My bet is that he somehow captured an Ascian and gain the intel about the source and the reflection. I can't think of any on how he would know. And do not forget that he look really young and the Endless didn't exist until Otis volunteered to be experimented when he was an old man. So we can't be sure if Calyx an Endless or if he learn how to life without a body like the Ascian.
There is so little information about Calyx and his organization.