In Noblesse Aura doesn't have a set effect it's something that can be used in a multitude of different ways but it was always states that Aura came from the soul so it wouldn't be a stretch for someone with control of Aura to support one else's subconscious especially if that person doesn't have any Aura at all.
Aura can be used to form blast like ki from DBZ it can also be used to fly, physically enhance the body, and craft thing with supernatural effects.
Aura was also shown to be able to take the shape of natural elements like lightning.
Aura is also said to be invisible to the naked eye for those who don't have access to it.
Aura allow one to sense other emotions and detect one's location.
Aura can act as a catalyst to unlock other special powers and abilities.
Aura also allows previous clan leader to past down weapons through the soul when someone's becomes the new leader and each weapon has its own Aura.
(If you have any questions leave them here J will try to answer them)