Honestly, I was worried the meeting was a set up. What do we really know about Cassiel anyway? Nothing. At one point, I even wondered if he was part of Kage's death. After this meeting, I don't think that. It's clear Cassiel cared deeply about Kage and his overall wellbeing (as much as someone can in that line of work.) I also think there was some closure here for Elijah. Maybe closure is the wrong word, but he just met a big part of Kage's life.
How can Elijah ever love again?!