I'm writing one now. It's called "Lucario and the 10 Ordeals". You can find it at the fanfiction forum or at fanfiction.net.
It's an Adventure/Suspense story, where a Lucario named Zeke ventures out into a forest, finds a portal, and is teleported to another world, where he faces 10 challenges. I'm currently on my fifth chapter. You can go to fanfiction.net to see the reviews I've been getting.