At the beginning of the Mario arc, the first guardian angel appeared in the bedroom and looks over to an unconscious bed who is wrapped in bandages.
1st Guardian Angel (Elder): Psst, Ben. Can you hear me? My name’s Elder, the leader of the Guardian Angels. But unfortunately, I can’t talk with you right now because I’m too weak to talk to you. If you want, meet us at the Cloud Nine Galaxy, me and the other Guardian Angels will be waiting for you there. (disappears)
When Ben wakes up, he finds himself in a Bedroom Dorm where Rosalina appears and she said that he didn’t open his eyes for many days and nights, she and the Lumas were worried sick.
Rosalina: You didn’t opened your eyes for many days and nights, me and the Lumas were worried sick.
Ben: (surprised) You mean I was being knocked out for that long?
Rosalina: You could say that.
After crying, Ben told her that he needs to go to Cloud Nine Galaxy to meet up with Elder and the Guardian Angels before going back to sleep and she left.