Upside down

On every students 17th birthday they're put under a test they are unaware of. If they pass at least two of the four subjects (speed, blending ability, group combatability, and fighting) they are put into the first world and their first mission is on a nearby sign. They have an unnumbered amount of worlds to pass through and almost impossible missions to complete. What they don't know is that they're doing exactly what he wants them to.