Aanen joined the monastery at a rather young age and lived there the better half of his life. In the monastery, he trained as one of the monks and learned martial arts, as well as ways to use his Ki and shortly before he left, how to control his astral form. 
Aanen left the monastery to carry out missions for it. He would go search ancient tombs and buried cities in search for artefacts, magical items and various other things that he would then bring back to the monastery. The reason he did it was to make sure these items don't fall into the wrong hands, as what happened with the nargels.
When the monastery struck a deal with the Holbright Institute to let the Institute keep the items that were held in the monastery for the public to admire, he brought his findings to them instead. (Alternatively, it happened right before the campaign began and he hadn't excavated anything for the institute yet.)
As part of the deal, he received a Wand of Secrets to aid him in his missions.

Backstory: Akanos Novak, the son of a Tiefling tavern keeper and a mother unknown to him, was born in the town of Regalo. While he grew up, his father cared for him, but was treated as a servant and never his son. He ordered him to sweep the floors, take out the trash, serve drinks, and other menial tasks. He never got the love from his father that he deserved. When he tried to go to school, he was bullied constantly and even humiliated by the teacher. Despite these obstacles, Akanos became an exceptional student, earning himself a scholarship to the renowned Banhaven Academy for Magical Arts at age 18. After graduating from Banhaven, he set out to become an archeologist. The next few years were very successful ones, until one day he discovered an ancient temple dedicated to the Archdevil Mephistopheles. While exploring the temple Aknos discovered a Medallion of Thoughts, but there was a cave-in, and Akanos became trapped. After four days, he was on the brink of death. Right before his life was about to expire, he was visited by Mephistopheles himself, who had been observing Akanos for some time, interested in his magical power and scholarly knowledge. He offered Akanos a choice: become his disciple, and he will save him, or, stay in the temple and die. Seeing no other alternative, Akanos made the deal with Mephistopheles, granting him extraordinary magical power. In a flash of light, Aknos was teleported outside the temple. When he returned to civilization, he saw the recruitment for Holbright's Insititute of Higher Magics and applied. H could use a break from traveling alone and he missed his years at Banhaven.

Personality: Akanos is very kind, despite his youth past, and is willing to make new friends. However, he knows he is a Tiefling, which means people will judge him before they know him, so he tries to break the stereotype and be a good person. Nargels

Zadra grew up inside a city of mostly humans, and knowing absolutely no other drow for the biggest part of her life, she considered herself one among them. Despite being an orphan, it hasn't marked her all that much, as the career she had started in her later years would define critical aspects about who she was. Her job involved swindling and stealing, so she always got what she wanted, and much money was made from stealing from rich folks who would believe her stories. Problem is, it's quite a dangerous job.

One day, on the job, her victim was a noble of the Nargels noble family. The result was a success, despite Zadra leaving with no more money. What she stole was a magical periapt of great historical importance to the noble family. One day later, she was busted, the Nargels knew exactly who stole it, and Zadra had to leave.

Lately, Zadra's learned of a strange affinity to the psionics she doesn't yet understand, but it helped her find somewhat of a living on a thieves' guild, stealing in the traditional way, as her face doesn't need to be seen for that job. But, it wasn't gonna be enough. At least, not to the ambitious Zadra. She hid her criminal background along with her former identity away and advertised herself as an expert dungeon explorer, leading eventually to her being sent on a mission thanks to the Holbrights Institute.

Periapt of Wound Closure

Gold: 6 * 10 / 12 * 10

To the north of the continent is a frozen land, but one rife with life. Glaciers have carved massive fjords in the coastline, and the dark cliffs are covered with mossy pine forests. The people who carve out a life in these wild lands make a living as fishers, hunters, and occasionally raiders. These hardy folk celebrate their lives with nightly feasts in mead halls, where female storytellers called shieldmaidens keep spirits high with grand tales of heroes past over roaring fires. To be a shieldmaiden is a calling, often reserved for the daughters of chieftains, where the young woman learns both the oral histories of the village and martial prowess. A shieldmaiden’s battlecry is so impressive that allies are bolstered and enemies cower in fear. There is an ancient magic invested in the calling, which only a rare gifted few can access. These were called valkyries by the villagers, their songs said to carry the weight of gods.

But that magic has become unpredictable in recent times, and shieldmaidens who could tap into it became viewed with suspicion and hatred, as ruin and woe were likely to follow this magic. Witch became a more common name for these rare warrior-women.

Erika, daughter of Grimus Faronsson, is one such shieldmaiden. Raised in the old ways, she surprised all in the mead hall one night when her retelling of the story of Regnar the Bold’s battle with the Ice Drake unintentionally summoned an image of the battle as it unfolded. Facing exile or execution, her father instead spirited her away to the home of an old crone - an elderly shieldmaiden who could tap into the same magic. Here, Erika learned how to refine her control, as best she could. The crone was a harsh mentor, but fair, and nights in the small cabin were spent telling the stories of old. 

Eventually, the crone had taught Erika all she could, and bid her to go into the world. Before she departed, the crone gave Erika her shield, a bright steel round shield painted with the watchful eye of Garm, guardian of the underworld. This shield had saved the crone’s life many times, and so she hoped Erika would find a long life bearing it as well. Erika departed the small island and traveled south. She longed for the chance to return to her village a glorious hero with a hundred new stories to tell, instead of a shamed exile. When Erika saw the offer of this strange Institute, she saw an opportunity to delve into why her gift became a curse, and to truly shape the path of her tale.

nargels 

Sentinel Shield

Gold: 12*10 / 7*10

Erika is a tall human woman with long red hair kept in a tight, elaborate series of braids. Her skin is tanned from much time spent outdoors. She is well armored, wearing steel scalemail that has some similarities to dwarven design, over a heavy leather jerkin. The edges of her clothing are lined with fur, as is the long gray travel cloak she wears. She has a wild, untamed look about her. A large round shield is strapped to her back, along with a battle-axe.

Molle was born in a rather unremarkable village in the countryside, in a large family of farmers. Growing up, she felt like a big fish in a little pond, so as soon as she was old enough, left her village for a big city. She was confident that she would be able to make a name for herself, and end up living a comfortable life as anything but a farmer. That anything part came to bite her in the butt. Getting work was difficult, and she often at the start worked whatever menial jobs needed filling. One evening, after finishing one of those jobs, she came across a man who was offering stable work for anyone willing to get their hands dirty. Taking it a bit too literally, and in need of a consistent job, she took the man's offer. Which, it turns out, was for the 'legitimate' business of a large criminal organization.

For the next couple of months, Molle worked in moving the legal products. After defending a wagon against would be thieves (and competition), she was offered a better position in the criminal part as an enforcer. Training, better pay, and some benefits included. Jumping on the opportunity, Molle took the offer. Working under an experienced enforcer, she gained many new experiences and skills, some not always wanted. Especially one such incident with nargels. For several years, she worked with them, but over time became rather unsatisfied with her occupation. Yes, she had made some friends, and was trusted enough to be given a magical item to help her (in her case, an Eversmoking Bottle to help with escape or raids), but she increasingly didn't like the tasks being given to her. Dying in a gutter over a petty rivalry was not a way she wanted to go. So after that nearly happened, she decided to get out. Taking everything she had, Molle decided to turn over a new leaf. One that was hopefully less taxing on her conscious.

Now advertising herself as a mercenary for hire, chess tutor, and duelist instructor, Molle makes less gold, but is more content. She doesn't hide away her more unsavory past, but only brings it up if directly asked about. Now, she tries to take reputable or big jobs, in hopes that she can someday get a little bit of fame she's been hoping for.

Ayla was broken. At least, that's what everyone told her. No orphanage wanted to keep the girl who uncontrollably shifted between faces, scaring the other children, so she was eventually thrown out onto the streets. She struggled to survive for years, picking pockets and fending off the rats and nargels that tried to steal her meager food supply. Then she met the glowing figure from the sky. They fixed Ayla, letting her stay in one form for as long as she liked. They gave her other gifts, too - magic to heal and harm, a wand to channel her newfound abilities (Wand of the War Mage, +1), and eventually, a tiny silver dragon to keep her company. They didn't ask much in return, just simple requests from time to time. Go to this town. Take this job. Meet this person. She still isn't quite sure why they're doing this or even who they are, but she figures completing these tasks is well worth the payoff.

(I intentionally left her patron vague because I wasn't sure what pantheon we're using. I'm imagining a deity associated with either the life or light domain though.)

Disguised form:

True form (featuring my terrible photoshop skills):