Vhem, a Quarian? owned by Aria.

First of all you are not a quarian, you're a human wearing a customized exo suit to counteract your severe sunlight allergy. This allergy is the result of genetic engineering by Cerberus. It's the reason they decided the project was a failure even though you did get the planned upgrades of increased hearing, smell, sight, reflexes and perfect night-vision. They chucked you and the other failures in an escape pod with deadly gas and ejected it. When scavengers found it you were still alive and killed everyone on that ship but the pilot who got you to Omega, that seemed to be the best place for a genetically engineered teen with sun allergy to go.

As you stole and killed to survive Aria noticed your potential and had someone customize a quarian exo suit for your use. After that she had people train you in combat and hacking, you thought she wasn't as bad as everyone said but soon realized you'd lose the expensive exo suit before you made her more money than in cost if you worked without training. The final part of your training was to kill your teachers as the only one allowed to remember your real face and live was Aria.

Now you are 23 years old and have paid off your debt to Aria for a year but decided to keep working for her as you're truly loyal to her and think she actually isn't nearly as bad as people tend to think, it just takes a hard hand to keep Omega in line and she enjoys being that hand. Aria may be a tough queen but she's a good queen, your queen and you would do anything for her. Getting back to her from the Citadel isn't that hard, just steal a small merchant vessel and sell it's contents on Omega. Aria got you out of prison so she's probably got an urgent mission for you so you hurry to her quarters unseen by any person.