Only real problem with your post is that your summon cant move from the spot he was summoned too. Its in the description for it.
EDIT: its in bold below
King of Flaming Hell
http://img239.imageshack.us/img239/8415/3mouthwm0.jpgThis demon is called the king of hell. Its the older brother of Mephisto and Baal. It's original name was "Marlou" in the demon language of higher cast this ment king. Marlou's abilities are actually simpliest of all demons.
This is for one reason, there is only one ability which Marlou can use. This ability is called revert. Revert can send any attack coming at Marlou back at sender, though the revert will also slow the speed of object sent back by half. Revert can only be used every second turn. (meaning there must be one post between the times revert is used.)
Even though Marlou can only use this ability, the two mouths in his shoulders are whole different things. Those two mouths can spit out fire, they are called the endless pits for good reason. The fire reserve in the mouths is unlimited as long as the summoner is alive. Marlou can only use these two abilities,
also Marlou can't leave from the area it was summoned.
Meaning that it can actually be mostly used in defence nature. Also Marlou can be sent back into the demon realm by destroying the two mouths. If this happens the demon will be forced back into the realm of demons.