This is the idea, we don't need pictures for this:
You make a post by replying, the last digit of the post you reply to decides which pokemon you can choose (see image and numbers for the pokemon). So if the last digit is 9, you can choose 009, 019, 029 etc. Up to 149.
You have to choose a pokemon which can beat the type of the last poster you reply to.
So for example:
No.64768932
Geodude
You can choose 02, Ivysaur, as the last digit is 2, to beat Geodude. Your last digit decides which pokemon others can choose to beat your pokemon. If nobody can beat it a new random pokemon will be choosen.
I 'll start with Articuno