Spider Web

Flip a coin. If heads, the Defending Pokemon can't retreat. (Benching or evolving that Pokemon ends this effect.)

Poison Bite20

If this attack damages the Defending Pokemon, the Defending Pokemon is now Poisoned and you remove a number of damage counters from Ariados equal to half that damage (rounded up to the nearest 10). If Ariados has fewer damage counters than that, remove all of them.