This is incredibly beautiful.
Great character interaction between the Pokemon! I love how you stylized Drifloon's head-puff to look more like a real cloud, and how Delibird seems to be wholeheartedly enjoying its flight. The life sparkling in Delibird's green eyes is a lovely touch, too.
The Pokemon alone would be awesome enough, but it's the backdrop that really pushes this over the edge for me. That skyscape is positively
glorious!
Those sunset colors, blended together softly and reflecting on the Pokemon... Wow. Serious wow. Regardless of the outcome of the contest, you've made a piece worth being very proud of!