You were on the right track and everybody started to ignore it. With no negativity to feed on, it started to fade. Of course, if what it says is true and it can now feed of its own anger, that tactic will no longer work.
Anyway, how do you plan on awakening the other fragments? Because as far as I know, a strong emotion would be needed to awaken one. Like when the fragment of rage fully awakened after absorbing the Charlotte from the alternate universe.
Eddie fell back after seein that his lightning bolts had little to no effect.
He took cover and waited for the moment when someone would require healing.