Chaining this with Unity could cause a one hit kill.
Use cards that will force your opponent to attack to be sure this card doesn't just sit around draining your LP. Cards such as All-Out Attacks, Battle Mania, and Berserk Gorilla (swich it to the opponen's side) will force your opponent to attack to ensure this card can help you.
This card works well in a Rock deck, especially with "Canyon" on the field.
Chain this to your opponent declaring an attack. It will catch them off guard, and unless they can negate the activation you have a 50-50 chance of causing some heavy damage. As an added bonus, if they were targeting an Attack position monster, their monster will be destroyed.
The only cards that can increase a monster's Attack when this card is affecting that monster are effects that activate during the Damage Step. As such, cards like "Honest" will only match and not exceed the other monster. This becomes a -1 when your opponent has to decide if they want to use "Honest" in order to destroy your monster - theirs is lost already.