"Can you explain the 'Emily is the UA traitor' AU?"

Sure.

Ok. First of all. Emily can never get a hero licence in Japan since she "came" from America.

For simple explanation, Emily is a foreigner and can get EDUCATED in Japan but cannot be an official HERO in Japan since she was not born there.

This AU sets the scene for Emily is lie about her origen and her quirk. She is actually from Japan but is very good at mimicking accents.

Emily's quirk in this AU is called "Atomic Bomb". You can already guess how powerful she really is.

She is also using Kishi as a scapegoat so she has cover.

Remember, Kishi is Stain's daughter. Kishi was the first interrogated for being the traitor. Iida strongly believes she has something to do with it.

Emily is at UA for three reasons.

1) Constantly collect data on other students/teachers

2) Inform LoV of internships, events, and other things that makes it easier to attack UA

3) Make a plan to capture Kishi

She basically reveals herself when her, Iida, and Kishi are in a team and they get cornered by LoV.

Iida gets a good old slap of "think before you assume" as Emily basically tells him that "you are an idiot for thinking Kishi, the girl with the opposite quirk of Stain, could do what he did".

Aaand yeah. That's the AU.

Other AU I have is:

Urufugāru and Shoto are half-siblings