This is self explanatory, and you choose one Pokemon or the Pokemon that you chose from the become your Pokemon game and you attack the one BELOW you, but you can only use moves from Pokemon like solar beam, brick break, and such. DON'T use anything other than Pokemon moves and they have to be 50-100.

Sceptile Lv 70.
Uses False Swipe and hits whoever comes in next and reduces that Pokemon's HP to 1