Jo De Mora Was A Exceptional Soldier Trained In North Ares To Stop Terrorist And Other Raids.

Later She Start To Sell Weaponry To The Mercenaries, Bounty Hunters And Pirates To Gain Money. She Got Caught By Tekvian Soldiers And They Send Her To Tekva Research Asylum.

At The Same Time Tekva Scientists Developed A Drug Called Valkyr Capable Of Enhance The Soldier Capabilities Such As Strength, Speed And Their Five Senses.

De Mora Was Chosen As Test Subject Injecting Her A Large Dose Of Valkyr Making Her Go Crazy And Berserk Destroying The Research Facility, She Got Neutralized By A Member Of The Valkyrie Team And Sent Her To A High Security Mental Institution.

That Institution Was Really Another Research Facility And Use To Investigate "The Maker" and The Necromorphs.

An Incident Of A Religious Scientist Trying To Move The Marker Set The Necromorphs Free, And Start To Killing And Roaming Around The Facility Giving Jo A Chance To Scape From Her Cell And Start A Worst Raid Than The Necromorphs Just To Know About "The Marker" But She Got Nothing Since At The Start Of The Incident The Valkyrie Team Retrieved The Marker.

Since That Incident She Joined To A Stranded Covenant Army And A Exiled Locust Army And Formed "The Vikings" To Find The Keys To Open The Tekva Underground Facility To Get The Marker And Start Her Kingdom.

She Still Have The Concentrated Power Of The Valkyr In Her Veins And Keeps Feeding Of That Evil Drug.