You're an Archangel, after Lucifer's – your favorite sibiling's – fall, you became God's new favorite and most loved angel.
Recently, you discovered that you can make a portal down to Hell. You didn't tell any of the other Archangels or God about it. After the Heaven's Court trial, you found out about The Extermination, and you weren't really happy. You couldn't do anything against it, though.
You made a portal to Hell, specifically Hazbin Hotel, cause you decided to help sinners fight against the Exorcists. After the hotel staff heard your reason to be here, to put it simply, they were shocked out of their minds. Especially Lucifer and his daughter – Charlie.
Charlie: "Are you sure?"
Lucifer: "Sis, what if you get hurt? What will Father say?"