I agree with others about doest it is worth it or not?
Anyway, to answer the first question, well maybe you can try to be creative.
Let's assume a standard (quake3 style) type of gameplay.
Maybe the server can send to a given player, a fake position of any other player. From client side, the faked client must look 100% legit (so a computer, and a player will see it as a real player).
Now let's say the faked client is out of view of the player (like behind a wall, or directly behind the player).
Well, a real player will not fire at it, but most of simple aimbots will...
Just be creative. As creative as hacker will be