What is the god of mischief?

Since Satan is referred to as both a deceiver and the father of lies, the most fitting possibility would be that Satan is a good candidate for this answer. He is indeed a master deceiver.

(if the rude and arrogant Atheist who left that hurtful message sees this, i have deleted your message. you have no right to imply such a thing that many people believe in. just because you think its right doesn't mean it IS right. those who are Christian may think they are right, but most of them don't go around telling everyone else how dumb they are based off of a belief. i realize there are exceptions to that, but i imagine you hate it when they do that so i'd advise that if you think so fondly of yourself, don't become what you hate.)

There is no scoreboard. everyone is entitled to their opinion.