[a nod, and Akira lifts a hand to place it over his heart]

Everyone has a mask with which they face society. Something that helps them cope with adversity. A "Persona," so to speak.

A select few of those people can manifest that Persona into a physical being to fight for them. That Persona usually takes on the form that best represent's that person's soul.

[and then he drops his hand back into his lap]

I can't use that ability anymore, but it's still something "abnormal." If you want to call it that.