Frankly, it would've been prudent for us to have gotten a hint here about Glion's eventual comeback at the Shinou League, yet Glion was left behind without Satoshi promising to retrieve him later from what I remember.
I really liked this “goodbye” for Gliscor. Personality-wise Gliscor is my favorite of his Sinnoh Pokémon; so fun as well as just being cool and good in battle as well. Gliscor gaining courage and the will to get stronger and stay to train was executed very nicely. I loved seeing Dawn and Ash help it train to feel the air.
Gliscor being a crybaby but resolving to stay was so cute and nice, and that goodbye at the end def pulled at my heartstrings. Even TR didn’t want to interrupt lol