I already have a name for the evil team... Black Ice... They are ninja's that specialize with Dark and/or Ice type pokemon... Black ice is a special type of ice that appears on roads that means that you can't see it and you slide A LOT if you're not careful. These guys come out of nowhere and will try to steal not only pokemon... but also your potions, and battle items. Ex: a person gets defeated/robbed by these guys... they took their Max Potions, Silk Scarfs, and other type specific items... These may also include the power items... Like power weights, which decrease speed but increase your base speed after every battle...
Just another note: Please put the name of the New Battle Mechanic you are suggesting... Just so I don't fry my brain... It took me 3 days to think of a name of the region... and I just realized I could use translate to translate Freedom from english to japanese and got "Jiyu"...