It nerfs your vehicles too, doesn't it? When they become creatures, they also become 1/1s.
An odd card for sure, it seems to have limited use besides nerfing your opponent's guys. Lion sash is a great target, though.
For EDH purposes at least, it is another(?) way to take infinite turns with Sage of Hours in mono blue. All you need is a card like Riptide Chimera or Words of Wind and enough mana to cast this for at least X=4 (since Sage will always get one counter just for being targeted each time). Janky infinite turn combo here we go!