Aaron is the Bug type Elite 4 member in the games Diamond, Pearl & Platinum. Where his team in Diamond & Pearl consists of Dustox, Beautifly, Vespiquen, Heracross & Drapion, which is decent, but provide a good rock, flying or fire type and you should have it easy for most his team, with maybe a good ground type for the Drapion. Then Aaron's Platinum team consists of Yanmega, Scizor, Heracross, Vespiquen & Drapion, so basically Dustox & Beautifly got replaced by Yanmega & Scizor, which that alone makes his platinum team much better than his Diamond & Pearl team. Again though, provide a good fire type, alongside a good ground type for Drapion, and you should have it easy. Rock & Flying could be good as well, just you'd want fire for the Scizor. However, Aaron's design isn't really one that stands out greatly to me, and although I did debate on ranking someone else out here over Aaron, I ultimately decided to take Aaron out at this spot.
Members Left:
Lorelei
Bruno
Agatha
Lance
Koga
Karen
Sidney
Phoebe
Glacia
Drake
Bertha
Flint
Lucian
Shauntal
Grimsley
Caitlin
Olivia
Acerola
Coming in at #19 on my ranking is: