Definitely Grimm.In Malucia's case it was way too obvious that her specter would break from all the overloaded magic,causing her top lose.Grimm on the other hand used manipulative tactics to make Raven sign the storybook and his plan almost was almost successful if it would have been for Cedar that told everyone that it wasn't the real storybook.Also,nobody would knew that he tricked Raven,if he wouldn't have been stupid enough to tell Raven that she saw that vision in a well and not in a mirror.

But Grimm had no magic. Even though he was able to imprison the Evil Queen inside all mirrors, Malucia stole the magic of many- she took away the wings of fairies AND drained the color from the kingdom of Zinnia. If Grimm had a magic scepter, he could have probably sucked the magic out of Cedar Wood's revealer rays. That way, no one would have known that the Storybook Of Legends Raven Queen refused to sign was a fake.