Her name is well deserved, as she’s the daughter of Insanity and Fear.
Macu spends his time looking for kind and giving people who he rewards in some small way. He does this by disguising himself as a needy person, maybe an injured traveler on the road, or a beggar in a town. The first person that responds kindly to him will receive some assistance in the endeavors, they will find out about the assistance when Macu has finished helping them. If a party member is simply indifferent to Macu then Macu will give the party another chance, in a different situation, if the party is still indifferent then he will leave them alone without interfering with them anymore. If the party is cruel or evil in anyway to Macu then he will punish them is some suitable way that matches their evilness. He will even show himself to them so that they will recognize him and the fact that they were evil/cruel to him.
Magical Fiends: When a mage or wizard casts a spell and draws more energy than s/he needs Magical Fiends are drawn to that spot and they feed of the extra magic as long as they can. When someone's magic is being fed off of they can't cast spells as well and they feel weaker. The only way to remove a magicial fiend is for it to be drawn away by someone else's power or to go to the very spot you first cast the spell and kill them