Good start to the great hunt looking forward to seeing where this rolls off to now that Stella has met rune and has gone back is she going to study light and dark? or once he's healed she going to come find them again
Stella will come back later in the arc. You don't have to worry about that. She will fully join the MCs group during this arc. As for her learning light and dark techniques, I set it up so that she could potentially, but I'm not sure yet.