As I have mentioned previously, I love the 20 Questions used as part of character creation in Legend of the Five Rings.
It may have taken me a bit of time, but I finally have a version suitable for angelic characters (the same list could probably be used for demons as well with only minor tweaks).
Please comment on the questions. I’d love to learn which you found to be helpful, and which were so much fluff.
1. What name do you go by?
Some angels pick entirely new names for their mortal personae, while others adopt approximations of their heavenly name. No one will use their true heavenly name because it cannot be conceived of or pronounced in any mortal tongue.
Need some suggestions? Try: On the Naming of Angels and Demons.
2. What choir do you belong to?
In many ways this is the most important choice you will make, as something of your nature would follow you even into Hell. Have your choir in mind? Good, now take a moment to think about what your choir represents: truth, protection, motion, &c. How well does your nature align with that of your choir? Do you ever wonder if you have more in common with the band of demons you oppose? For Malakim, what choir did you have before and do you ever want to go back?
3. Which Archangel do you Serve?
How well do you get along with them? Did you serve a different Archangel previously – and if so why did you leave? Even if you’re an Outcast it’s worth considering which Archangel you served before and whether or not you still have dealings with them.
Not sure of your options? Look through: A List of Canon Archangels
4. Do feel closer to your Superior or their Word?
The Superiors might think that they and their Word are one and the same thing, but their Servitors know better. It is possible to serve both, but many angels prefer one or the other.
5. What role did you play in opposing Lucifer?
Were you a messenger? A scout? An artificer? Did you face down any notable opponents or watch anyone important Fall? Did you take the oaths of a Malakite? If you did not exist at the time of the fall, when were you born and when did you fledge?
6. Do you have any friends on the other side?
Not all angels are as idealistically pure as Dominic or Lawrence might like. Some have old friends from before the war whom they are still sympathetic towards. Others, have made new allies that might not go over so well with the Seraphim Council.
For example Michael and Ba’al were great friends before the Fall, and are rumored to still take beers together from time to time.
7. Have you made any angelic enemies?
Not everyone in heaven sees eye to eye. Is there anyone who would like to see you face a tribunal of Judgement? If so, what did you do, and would you reciprocate?
8. What is your gender?
Most celsestials are agender beings of metaphysical energy. Does that describe you, or do you have a more pronounced gender? Does your gender change at all depending on your host and vessel? If so, how?
9. When was the last time you were assigned to Earth?
Many celestials go their whole existence without ever setting foot on earth. Others practically commute there on an annual basis. If you were on earth before, what was going on while you were here and why did you leave?
10. What is your take on humanity?
Jordi thinks they’re a hindrance, David thinks they should be strengthened, Zadkiel would rather protect them, and Yves thinks there the key to everything. Do you follow one of the Superior’s paths, or do you have your own philosophy about the little dreamers?
11. What is your highest ambition?
Ambitions can lead to sin if handled improperly, but ambition tempered by duty and loyalty is often acceptable and encouraged, and the nature of that ambition can say a lot about you. Do you want to make peace between your Superior and a rival? Catch an opponent out in an unforgivable transgression against the law of heaven? Maybe you’re interested in the respect and authority of a Distinction, or even the raw power of a Word.
12. Given a day to yourself, what would you do to relax?
Even angels get some occasional downtime. What sort of things do you do to reward yourself?
Looking for ideas? Consider Sixteen Things to do With Downtime
13. How would you describe the state of your Superior’s Word?
Even a completely loyal angel may have thoughts about how their boss manages things. What do you think they’re doing right and wrong? Which enemies would you want them to make peace with? How have they handled the question of humanity? The question of Hell?
14. How would someone else describe your appearance?
Consider both your favored vessel(s) and your Celestial Form. Every character needs a rough description in order to give them life when you describe them to others. What’s your most striking feature(s)? How lively are your expressions? Is there a certain feeling that follows you into a room? Are any past traumas etched upon your celestial visage?
15. What are your greatest strengths and weaknesses?
Strengths can be described as the things others are likely to admire a character for while weaknesses are what they try to hide, avoid, or correct. However, this is not a job interview. No one wants to play with the perfect angel. Your weaknesses are part of what will make you interesting as a character.
16. What prejudices do you harbor?
In addition for their common disdain or contempt for demons, almost every Superior has a negative opinion of another Superior and their servitors. Do you share those biases? Have others of your own? What’s your take on discordant angels?
17. What are your most and least favorite things?
Not everything about your character needs to be of earth shattering importance. Likes and dislikes can breath real life into a person – especially if you think about why.
18. How would you handle a human’s sinful behavior?
Humans are not perfect. How you would intervene in the life of one who has lost their way can say a lot about how your choir, Superior, and personal priorities will interact. After all, if a soul falls to the other side during your watch, it reflects poorly on you and your Superior.
19. Are you religious?
Angels don’t need faith, they know God is real. And yet many find great value in mankind’s teachings on the subject. Do you believe? If so, how deeply and which faith? Has this colored your relations with your own Superior, with others?
20. What is your greatest virtue? Your greatest sin?
Feel free to use the 7 Heavenly Virtues and 7 Deadly Sins as a jumping off point, but don’t feel like you are limited to this paradigm. Any philosophical structure which includes virtue and sin is fair game.
Book of the Neglected 
Bonus Question (stolen from the memeiverse):
If someone wanted to summon you, what 3 things would they put in the circle?
Answering for one of my NPC ideas, Hope, Angel of Redmepiton, Master of Peace:
1. Hope.
2. Mercurian.
3. Novalis.
4. Superior.
5. She’s a Psyops sort, with a focus on Redeeming demons, usually Renegades, as well as social skills. She’s a skilled negotiator, with a particular talent for figuring out compromises.
6. Obviously, given her job description, she has quite a few. Mostly Renagades, but she has a few aprticuarlynoble Demons as “pet-projects”.
7. She has quite a few. Mostly over-zealous Malakims, but quite a few others are leary of her, especially the Servitors of Dominic, That said, her best friend is actually a Davidian Malakite: Chark, Angel of Cooperation. In public, they make a big show of having a rivalry going on, but no one would be fooled for a second. They’re grateful for each other’s work every day.
8. Female.
9. Only a few weeks ago.
10. She loves them. They can be a great people, and all they need is the right push.
11. She’s Redeemed a lot of powerful Demons: Several Knights, quite a few Captains, and even a couple Barons. Her greatest ambition, what she believes is her Destiny? Be the first to Redeem a Demon Prince.
12. Study, talk with people, watch TV shows, tinker with Legos, eat…She has a lot of interests.
13. Could be better. She wishes she wouldn’t work with Jord, who view of humanity she detests.
14. Blond hair, looks very waifish and skinny. In Celestial form, she looks the same, but with wings, and her hair goes from blond to outright banana-yellow.
15. She’s very skilled at persuasion, and will always try to help people, but she’s also very forgiving, and will extend the hand of friendship to anyone. She can also be passive and even a bit of a doormat.
16. She’s not a big fan of Dominic or David, and she’s not hot on Jordi, either. That said , she’s surprisingly fond of Laurence, even if his Angels tend to be suspicious of her.
17. She utterly hates dirtiness and germs. That said, she has a deep love of bathing.
18. Try to convince them to change or make amends. She’s convinced beings far worse.
19. She’s not very religious, but she LOVES Jesus. He was the Son of God, and better then any Angel,and his human viewpoint made him so. She’s, in human terms, a “Red-Letter Christian”.
20. KIndness and Pride. Just a little of the second, though.
Also, some backstory:
Hope was born shortly after The Rebellion. She fledged around the 600s, and spent centuries as a random Servitor, working for Novi, developing her skills. Back then, she was somewhat bland and cynical. She believed in Redemption, but was not optimistic However, the battle against Legion changed everything. She worked as a strategist and battlefield coordinator, but in this capacity, she worked with several Demons., wherein she learned how much comlex they could be. The idea that even a Demon could have a spark of goodness changed her. She threw herself into Redemption. She kept up relations with several of the Demons she met during the battle, convinced quite a few to go Renegade and even Redeem. She was found quite impressive, and Novalis gave her her first title as a Vassal. He kept up the work. By the early 1700s, she’d Redeemed hundreds of Demons, and she was given her Word. As of the time the Campaign takes place, (2001),she’s being considered for a promotion to Archangel, partly because she played a major role in pulling Khalid back from the edge,and partly because, what with the chaos in the world, the Archangels could use a unifier. Her friend is also being considered…