Once per turn, before damage calculation, if your monster attacked an opponent's monster: You can change the battle position of that monster your opponent controls. Once per turn, before damage calculation, if an opponent's monster attacked your monster: You can change the battle position of that monster you control.
Can change the battle position of your opponent’s monster when any of your monsters attack.
Can be used to protect your monsters by changing the battle position of an attacking monster.
Can only change battle position when a monster has attacked.
When you attack, change the battle position of your opponent’s monster to the lower stat so that you can easily beat over it.
If you have high enough attack, you can change your opponent’s monster from defense to attack position, this is also a good way of checking your opponent’s set monsters. Most effective for high defense monsters with low attack like Big Shield Gardna.
You can use Kabuki Dragon to change an opponent’s monster to defense position if it would inflict more damage. Here are monsters that can inflict piercing damage.