All beings of the universe live in Nine Realms that center around the tree Yggdradsil. The gods live in the heavenly world of Asgard, while the humans live on Midgard, which is somewhere near the center of the life tree. Jotunheim is the land of the Frost Giants, Svartalheim is home to the Dark Elves, Nidavellir the home of the Dwarves, Niflheim, the world of the dead, Muspelheim, the world of fire demons and ruled by Sutur, and Alfheim, the land of elves. Asgard had a sister race called the Vanir, who lived on Vanaheim, though not too many dwells there any longer. The Vanir were greatly associated with incredible gifts related to nature, fertility, and future-seeing. One of the most notable gods linked with Vanaheim is the god Njord, the god of the sea.
Njord had several children with multiple suitors, as did many gods in the old days, but once he moved to Asgard he met a woman with the gift of healing and the pair settled down in a cottage by the sea and they had a child who they named Karina. Karina grew up in Asgard, surrounded by warriors and gods, and she herself was gifted with the ability to control the waters and heal wounds with a simple touch. She found favor with Odin as a child and quickly befriended his sons Thor and Loki.
Thor, the god of thunder, grew up to be a handsome young man who became quite boastful and proud. He was strong and he knew that, and Odin help anyone who stood in his way. Karina would join him and his friends the warriors three into battle, where she would fight alongside them and heal them as the fighting went on. She was strong, but her favorite moments were spent at home by the water or with her beloved: Loki.
Loki was nothing like his brother. He had gifts beyond Karina's comprehension and from a young age, he loved to get into trouble. He would often craft elaborate jokes and ruses to trick his friends and he would use his ability to create multiples of himself to throw off enemies. He was crafty and fun, and Karina took a liking to that. The two quickly fell in love and they were even set to be married, though that came crashing down when Loki found out that he was not of Asgardian blood at all. Instead, he was a Frost Giant, taken from his home when Odin last battled there, and he was raised as Odin's kin alongside Thor for over a thousand years, never knowing the truth.
Karina never knew how she would react to finding out that she was adopted. Perhaps she would be angry. Perhaps she would question her life and her upbringing, wonder what life could have been like if she were raised with her biological parents, but she would never understand how Loki would shun his family and look on them with hatred. Odin and Frigga loved him with all their hearts. They raised him as their own- he was their own, but he could not see it. He became paranoid and jaded, and he blamed his lack of Asgardian blood as the reason he would never claim the throne.
Thor was banished and sent to Midgard after attempting to enact war and after Loki found out that he was adopted, Odin fell into a coma, which granted Loki the rights to be acting king. It was this moment, Karina believes, that changed Loki's life for the worst. It hardened his heart and gave him the first taste of power, gave him the courage to begin his descent into evil. He possessed the tesseract then staged a union with the Frost Giants only to turn on them, killing their leader Laufey as he attempted to kill Odin, all one giant ruse to paint Loki as the hero, as the man who deserved to be king. Loki sent a godly weapon to Midgard to try to kill Thor, to secure his place as king, but everything fell apart. During all of this, Karina stood by Loki's side, begging him to stop this. He did not need to be king. They could be happy together, Loki was her king, her leader, her world, but Karina was not enough for him. Nothing was enough for Loki. And in the end, Loki failed. While trying to pull off his last trick, his last attempt to show himself as powerful, Thor tried to get him to rethink his choices and be his brother again. All could be forgiven if he just stopped all this madness. Loki instead let go of his brother and fell out of the Bifrost and into the vast abyss of no return.
There was mourning. Everyone was sad for Loki's passing and Karina took it the hardest. She blamed herself; why couldn't she have talked him out of it? How was she not enough for him? Loki could have been stopped if she would have been strong enough. Her mourning was short lived, all things considered. Because while she was mourning the loss of the love of her life, she discovered that Loki was alive and well on Midgard, ready to stage a new war, one that he would win. In the end, Loki would be king. He would get the respect and adoration he deserved. And Midgard? This planet was filled with uneducated and weak humans, it would be simple to overthrow. So, he thought.