>>52520584Not explicitly, just yet. Could be anything from "because he's from our world, and therefore something is different between our version of humanity and the Pokemon world's version of humanity" to "because she started as a vulpix in an emulated ROM of RSE before she became 'real' upon insertion" or something else.
After her evolution, a lot of it will probably be attributed to the worldbuilding of "evolution stones have purity and potency grades, and Vulpix used one of the strongest and purest Fire Stones ever found to evolve into Ninetales."
Whatever the reason Lee and Ninetales are so potent, especially together, the author hasn't come out and said it yet. To my knowledge, at least. It's weird how much more capable he seems than the average human in Pokemon, but everything he does looks pretty mundane - like the "new moves" are just ideas it seems logical to try out. "What if, instead of a single Bullet Seed, you messed with the move and tried to fire multiple seeds at once? Oh, that works? Shotgun seed, cool. Wait, what if you traded a bit of firing speed for a lot more power and accuracy? Seed snipe, gotcha."