After the twins were born, it was discovered that Mason had a heart defect, at one point he almost died, but pulled through, though the doctors said how long he would be able to live with his current heart without a transplant was questionable. As the twins grew, Erina did her best to raise Mason and Yavanna; she found a good job in London and was able to afford moderate luxuries for her and her kids. As the twins entered school, at first things seemed ok, but as the years passed, they showed more and more signs of some type of emotional disorder. They had a tough time socialising with anyone outside of each other and they started developing unusual preoccupations as well as coordination problems. At the age of seven they were both diagnosed with Asperger’s.
By the time, they were nine they were teased heavily in school, and relied on each other to get through each day. Mason spent a good deal of time sick because of his heart problem, even getting a simple cold caused his mother to worry that he might need hospitalisation. On the occasions that Mason was home sick from school, Yavanna would often try to fake sick to be able to stay with him so she would not have to go to school alone.
At the age of 12 disaster struck, on the way home from school one day a hellhound attacked, had it not been for a satyr watching over them, it may have ended much worse than it did. He was able to get there in time and get Yavanna a sword, but it wasn’t soon enough to keep Mason from getting bit and losing blood, he was rushed to the hospital and did pull through, but the event put a horrible strain on his heart. It was clear Mason was living on borrowed time, the satyr tried to convince Yavanna to go to Camp to train, but as her brother was now house ridden, and there was no way, demigod or not, she was going to allow Mason out of her sight, Yavanna refused to go. The satyr understanding her plight, agreed to stay living next door, to hopefully sniff out any monsters beforehand and warn them.
Over the next few years Yavanna withdrew further and further while at school, on top of Asperger’s, with her brother’s health like it was, she slipped deeper into depression, always afraid that each day would be her brother’s last. Shortly after the twins turned 15, the doctor’s told the mother that Mason had anywhere from days to a few months to live unless, he got a heart transplant, but due to a rare blood type, AB-, finding a compatible donor outside the family was proving impossible. By this time, their powers had completely come in, and Yavanna knew if she did not do something; her brother would be dead in a few months. Desperate she searched online for what it would mean to be a heart donor and how she could kill herself and still protect her heart. She knew she could not live without Mason, and she would do anything to ensure he lived, so knowing her mother could not swim, while driving across the Albert Bridge late one night, Yavanna screamed at her mother to stop the car. Confused her mother did just that, and it gave Yavanna the time she needed to get out of the car, and run for the side of the bridge, launching herself off, she could hear her mother’s screams, but nothing was going to stop her from saving her brother’s life, even if it meant ending her own.
By the time they managed to get Yavanna out of the Thames, she had not been breathing for nearly 7 minutes. Paramedics managed to get her heart going, but she remained unconscious, a few hours after reaching the hospital she was declared clinically brain dead. Her mother was beside herself with grief, but she did not want to lose both of her children so she made the decision to allow Yavanna’s heart be placed in Mason’s body.
By Mason’s 16th birthday, he was well enough to be back at home, the satyr that lived next door urged him to consider going to camp, as he didn’t have nearly as much training as his sister had, but Mason was depressed from losing his sister and started to exhibit even worse depression. Thanatos had been watching, and still mourning the death of his daughter, he did not want to see his son die after all his daughter did to save his life. Knowing if Mason had Yavanna back he would regain the will to live, Thanatos begged Persephone to turn Yavanna’s spirit into a flower nymph. Feeling pity, and being touched by the twin’s story, she agreed and created a black rose bush at camp for Yavanna. After this, Thanatos sent a message to his son in a dream, urging him to go to camp, for his sister was once again alive. Upon waking, Mason had to find out if it were true, and agreed to go to camp with the satyr. Upon reaching camp, he was both officially claimed by Thanatos and reunited with his sister.