That part with Mikoto felt somewhat unnecesary, only to please the fans, also this is because to much Mikoto is... annoying.
Thats why I keep saying more characters out of the cliche brings always a refreshing air to Index series
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P.S.: I'm the only one who thinks Touma needs more men as enemies instead sexy hot girls who will fall for him somehow? .... No, I don't want to see manservice .