So I have no clue where Spice City sits in relation to the rest of Japan, and I wasn’t paying enough attention to get where Saiki lives, either. Whoops. But lets assume that the two live relatively close, but not so close that Mob’s antenna would pick up Saiki.
One of Saiki’s most completely OP abilities is to convince every single person on Earth that something is true if he so desires it, and then change reality to match his desires and imagination. However, as we’ve seen in MP100, strong enough ESPers are essentially impervious to outside influence that is a certain level below their’s. In this case, this wouldn’t matter much as Saiki is demi-god level psychic, however, I figure that Mob’s strong auto-aura plus his natural hyper-denseness make him largely immune to these changes. This natural immunity has a slight field of effect so that Spice City has a lower incidence of the changes that Saiki made (aka weird hair colors and senses of style, a slightly slower healing effect, buildings take longer to repair, clothes can be torn away from crotches re:Teru).
just look at that body language and how telling of everyone’s character it is based on hand placement and posture alone
reigen: doesn’t know what the fuck he is up against, is acting as the leader and adult at the front of the group, obviously isn’t attempting to defend himself in the face of a psychic attack, dumbass still has his hands in his pockets
teru: both arms raised, knees bent, second one from the front. he’s defending, but his stance looks like he’s in attack mode as well. he knows how to handle a situation like this.
mob: one arm raised while the other is lax, he almost seems bored. he can simply defend all four of them by just using one hand. he also knows how to handle a situation like this.
ritsu: back of the group, doesn’t know what he’s doing. it isn’t clear if he’s trying to use his powers or if the pose is just him raising his hands in front of his face to defend himself. he’s scared and inexperienced.
I'm Still Kicking 