As soon as Sheyan rushed into the area, overlapping layers of terrifying illusions immediately assaulted him. This was the ability of the opponent, somewhat similar to that of Franklin, the deceased illusionist. The illusion could not be broken with simply a firm mind, so one could only get hit.
However, Sheyan had a different idea, because the enemy contained a lot of his viruses and his Perceptive Sense was also far above the enemy's! He could rely on the information transmitted to his senses to locate the enemy in the shortest time possible!
To explain it in a more visual term, this terrible illusion was like a labyrinth. Sheyan could sense the enemy's position at the other side of the labyrinth, so he could take shortcuts and move in a straight line towards the enemy. However, the enemy had surely set a lot of traps on this path.