AU where Diz is Irken.
She’s an assassin sent by The Tallests to just get rid of Zim once and for all but once she arrives on this “Urth” she sees just how hazardous he is to himself that she just kinda sits back and watches him go.
Her lie for sticking around him as that she’s a “Super Special Secret Agent” the Tallests sent to help him complete this mission. She lives in his base and just kinda. Mooches and lazes around.
It’s like a nice vacation for her.