The Japanese phrase in the original Hellsing that gets translated as “Angel of Death” is “shinigami”, made from the characters “shi” (death) + “kami” (god/spirit). The word for “paper” is also pronounced “kami”, and this is used for puns in the original R.O.D manga, as in “May the blessings of paper be with you.”
In the present-day Shineverse, Nenene and Michelle think it’s hilarious to address Maggie as “Angel of Paper.” (Anita always rolls her eyes at it, and nobody from Hellsing gets why it’s funny in the first place.)
Seras: It’s good to see you, Master! It’s been too long!
Alucard: Same to you, Draculina. And you, Angel of Death.
Or do you go by “Agent Paper”?
Maggie: “Maggie” is fine.
Integra (narrating): When Seras found Walter, she took him into custody, waiting for me to recover enough to decide his fate. He was in bad shape. Couldn’t fight off the brainwashing unless Maggie or I were present, and sometimes not even then. All three Paper Sisters were staying with us at that point.
When Walter was lucid, I offered to bind his powers to the Hellsing family; he declined.
Walter: Do what you have to do. Just take the girls out of here first. I don’t want them to have to watch.
Maggie…you need to be the one who does this. One day you’ll be glad of it. I promise.
Integra: These days, Maggie is our liaison to the reorganized and less-sinister British Library Special Ops. And Seras…
Seras: I’ll leave you two alone for tonight, because you have to make up for lost time. But if you try to monopolize her after this, don’t think I won’t fight you for her.