Hello, hello! Now we are starting to get introduced to the Espers of the 86 Universe. Let me explain a little bit about them.
Last episode, I gave y'all a breakdown of the major races in 86 and their respective colors & subraces. Now one of those subraces is what is called a "noble" race and people of those subraces can have the chance to develop a power, and those people are known as Espers. So far, only 1 race's esper power has been revealed and that is the power of the red race, the Rubelas. The noble subrace of the Rubelas is the Pyrope. Shin & his brother Rei, as well as Frederica, are all half Pyrope, as Pyropes were part of the noble class in the old Empire. Pyropes can develop an ability called psychometry. Essentially, it is the ability to perceive what cannot normally be perceived, but how you receive that information is dependent on what family line you come from. For example, the Giadian royal family which Frederica is from has their psychometry focused on sight. As long as they had talked to someone and knew their name, they could use their power to view the person's past and present, but not future. This is most likely how Frederica knows that her knight, Kiriya is now a Legion, as she must have attempted to locate him using her power and instead found him with the Legion (as he is a Shepherd, his conscious still exists so she is still able to see him. It wouldn't work on the Black Sheep Legion like Kaie though, since their consciousness is no longer there). Shin's family also has a psychometric power based on hearing - the ability to communicate telepathically with family members. This is actually the power that was replicated to produce the ParaRaid over in the Republic (remember that Annette was friends with Shin in childhood and her father was the one who helped created the ParaRaid using Shin's family's ability). Unfortunately, Shin's ability in its natural state is now completely unusable as his entire family is dead. However, he since he "died" and was resuscitated, his power shifted to not only hearing the voices of his family, but also the voices of the deceased. So Shin's ability isn't mind reading per-se, but telepathy.