The bad unicorn trilogy

After saving three worlds, Max has trouble settling back into middle school and life at home, but when he tries to return to the magical planet of Magrus, the evil Maelshadow begins changing humans into monsters in an effort to take over the planet.

"The second book in the Bad Unicorn trilogy features killer unicorns, good dragons, rogue fire kittens, and a boy who just might be a wizard"--.