After killing the two guards, if he couldn't kill the magus, it would be over for him, so this was indeed a risky move
He put strength in his leg and dashed passed the guards as quickly as possible, Rio knew the thinking speed of a magus, however, he also knew how uncreative they were
He knew that the first thing they would do would be put up a barrier and then proceed to attack
His sudden dash sent a wave of pain coursing through his body, but he gritted his teeth and continued his step
By the second step, the feeling not only intensified, but his thoughts became clouded, however, he continued
Before even reaching his third step, they realize something was wrong before Rio even landed on his fourth step, they quickly put up a shield
Too bad that the string was already within the shield before it was cast
Just like that, the four guards of the Central Plains died just like that