@Sprocket: Haha, thank you!
@Its A Random: You must grab the Drifloon at Valley Windworks.
Aww, it must be lost! You just found it floating there all alone; the wind is a powerful thing for an organism so light. You decide that you must find where the Drifloon originates from! Looking into every city and asking the gym leaders might help, as you never can tell what a person might know! Depending on its nature, you may only evolve it into a Drifblim once it solos one of the following gym leader's most powerful pokemon
Neutral nature: Veilstone gym
+Defense nature: Pastoria gym
+Special Defense nature: Hearthome gym
+Speed nature: Canalave gym
+Attack nature: Snowpoint gym
+Special Attack nature: Sunyshore gym
After many weeks of hard searching, however, it seems you cannot find where poor little Drifloon had originated from. But through your time and care, Drifloon has found a new home in the trainer that loves him so, and finally evolves into the mighty Drifblim! But even though Drifblim is happy with its new trainer, it still misses the place where it once had come from. Upon level-up, you must teach Drifblim the move Frustration. For the first turn in any battle that Drifblim participates in, you must use Frustration against the opponent. You cannot switch, run away, use an item, or use any other move on said first turn. You may not use Drifblim until you obtain the TM and teach it to it.
After beating the Elite Four, however, Drifblim realizes that no matter where you are or come from, you're always home when you're already where you want to stay. After this epiphany, Drifblim no longer needs to know or use the move Frustration, and you may do whatever you wish with your close friend.
Cheesy, complicated, based a little on luck, but good luck yourself.