Touma's power only works where he is touching, though. If that wasn't the case he could grab Accelerator and punch him with his other hand.
Touma nullifies the electric field that she passively emits, which normally deters animals from approaching her. after that, she can control her powers well enough to touch them
Touma's power only works where he is touching, though. If that wasn't the case he could grab Accelerator and punch him with his other hand.
As far as I can recall, the entire entity is affected: he dispelled whole illusions and unsummoned large monsters (namely Innocentus, who was a good 2,5m tall) by touch, not just a part of them. Also, somewhere in the first season, almost the same scene plays out, with Touma having a hand on Misaka's (or a Sister's) shoulder, allowing her to pet the kitteh.
As for why he didn't do that, I was asking myself the same question during that scene. Had he grabbed Accelerator's arm with one hand, his whole ability would have been suppressed, allowing Touma to beat the crap out of him with his left hand.