Me and my friends briefly played a pathfinder-based homebrew pokemon RPG (disclaimer: we trashed it in favor of a homebrew Runequest based pokemon RPG after like 0 sessions. There was some battle testing and some chargen for a handful of different homebrews and then we decided that the Runequest one was best. I still think this will work for you, though)
Double Team (Ex):
Speed 90ft or greater in any movement form. Ability to move at least 5 ft via that movement form.
The user moves so fast they appear to be in multiple places at the same time. Activating this ability requires a standard action and it lasts 1 minute per level. This ability grants a 50% miss chance that can be negated with a successful perception check DC users speed/5 or via any method that bypasses total concealment. While this ability is active you do not provoke attacks of opportunity by exiting threatened spaces. You take a -10 penalty to Reflex Saves to avoid traps or when forced to make a save by a terrain effect, however. You may end these effects as a swift action.
In the combat test the ability allowed one of the players to wipe the floor with the other team with his Dodrio, but it didn't work so good in the second round when the reflex save penalty meant he got hit by a stealth rock for a OHKO. I think the rules fit the effect you are looking for. Be warned, however, that properly made level 1 pathfinder characters can deal with a character relying on this (or similar) abilities quite simply, via effects like True Strike, caltrops, tanglefoot bags, etc.