Use this card when you use a Deck with a majority of your monsters that stay the same Level such as a Beatdown "Frog" Deck.
This card is brutal when used against Dragunity, Dark World, Gusto and Fortune Lady decks as their primary deck variations rarely have monsters of the same level on the field. Wind-Up decks are also at risk when a Wind-Up monster is summoned before it has the chance to change its level by card effect to match another Wind-Up monster on the field.
Chain the Graveyard effect of "Mischief of the Yokai" on the monster that your opponent selects to the targeting half of this card's effect in order to reduce its Level by 1. This will likely eliminate all the monsters that the opponent has aside the one that they targeted.
Change your opponent's monsters' Levels with cards like "Star Changer" so that they are forced to eliminate some monsters.