Cleo was brought into the pack because she had made it her purpose to impress Alpha Nera and prove her usefulness. She started as a pupsitter but quickly proved herself to reach further. So she was assigned as scout, and performed the role incredibly well for 5 years. She was retired just before her 7th birthday to become a mentor and help the pack learn.
She left her mate Fenrir behind when she left for the spirit world.