You read my mind~ 

All of the King's mages have some degree of skill in toying with the mind since they are the King's personal army and protectors. They were trained to break people. Their magic works better when they are together, especially if it os a type that they aren't the best in. 

For the next part I hope you don't mind if the mages summon animals or something similar to test them. The whole "run until six are left" made me think they would be getting chased.