Wow, I'm actually reviewing a non monster card today in the review.
Anyway, let's see it's effect.
Trap - Normal
Activate only when an opponent's card effect shifts control of a monster from your side of the field to theirs. Destroy that 1 monster and inflict damage to your opponent equal to its ATK.
Anyway, what does this do. Basically, if one or more monsters is gunna get stolen, you destroy that monster and do burn damage to it's ATK.
Now, you might say, "I lose MY monster, what's the point." Well, like they say, "If your not with me, your against me." Better to lose your monster then getting your monster STOLEN. Seriously, with the popularity of Monarch Control and all these aggro swarm, stealing gotten more popular even...