Wow, way to go Ash. You bond so well with one of your pokemon that it reaches new heights of power, then you give it away like everything else you've ever owned. I swear, Im honestly surprised he didnt give up Pikachu to the forest that one day.
It's been years since he explicitly gave up a pokemon. Before Goodra (which i'm not sure he's dropping back off at the swamp or not) the last one was... squirtle, I think.
Gliscor was temporary and is now back at Oak's like Charizard.
Doesn't make it any less funny that the pokemon where he had the super best ultra bond to make a huge ridiculous mega-level change is being given away though.