Although Roan wouldn't be doing as much as Rean, he could still move on the shadows and find the best spots. His perception is much better than Rean when they are not using Spiritual Sense too. One must remember that if Rean or Roan used their Spiritual Senses to move around in the Mission Hall, those at their level would feel it. Also, there was an even more significant reason for Rean and Roan to infiltrate the Mission Hall together.
"I hate it."
Rean shrugged his shoulders.
"There is no helping it since I need to use all my concentration for the task alone. Also, it's not like you will feel tired anyway. Besides, the smaller the area I have to cover, the better. It will be even better if I can leave all the movements to you."