Poor guy was pretty much collecting dust in my PC, he's much better off with you -- please don't feel like you have to use it though. He's probably my favorite tiny legendary, mostly because I saw that movie where he ate macarons, and I love macarons ♥
It's funny, because I never used any of those in my teams. My hall of fame teams were:
White: Serperior, Darmanitan, Seismitoad, Carracosta, Swoobat, Durant.
White 2: Samurott, Liepard, Ampharos, Arcanine, Lucario, Golurk.
Black 2: Leavanny, Krookodile (N's), Swanna, Stoutland, Magnezone, Jellicent.
I did drop some on the way, like Pignite, Golduck (I really wanted to use her, but she was so weak :(), and Panpour. And I've also trained and used Altaria, Starmie, Gallade, Clefable and others in the post-game battle facilities.
Maybe you should consider the remaining gyms and the E4 and champion's teams to chose your final Pokemon. Or is it more or less a blind run?
I'm... conflicted. I wanna do some more post-game stuff in my games, but I kinda want to play a challenge in some of the older games, like DPPt, RSE or FRLG. Decisions, decisions {XD}