Trina is a human witch who interfiered with the line of mortality and called Death to her to early.
Feeling bad for the misunderstainding Dee decided to bound her soul to his own.
Her soul now embodies that of a shapeshifting cat that lives in Dee's abode. Due to their souls being bound the two became close.
They are eachothers greatest advisors.
Rosy met Dee while working for Illumie's postal service, she would deliver his mail every week and over time forced her way into his life as a friend. She would insistently talk to him every week with her delivery to his home and over time he caved in and started enjoying her company.
Elvin is a orphaned child from earth who due to practices in dark magic ended up finding his way to Illumie. After being found by Rosy and starting to earn his keep in the Illumie postal service he came across Dee, who was already friends with Rosy. Dee very quickly came to care for Elvin and became a parental figure.
Mino owns the Illumie Flying Taxi Agency, passed down from his father, in which he uses dragons to have easier ways for people to travel around the Illumie isles. Due to Dee's own dragon rehibilatation system the two have done business before, but started to became close due to Rosy and Elvin's use of the service. Mino became another parental figure to Elvin, so the two also bonded over that. Dee see's Mino as a close friend.
The Prince is Dee's most complicated relationship. One that's filled with care and distrust. As the leader of Illumie The Prince has a lot of say in the going ons of the kingdom. And was the driving force for Dee's retirement from the angel of Death. Dee struggles with this loss and blames The Prince for it, but The Prince was also there for a lot of his healing process. The two trust eachother more than anyone else. Even with eachothers true names. But their relationship can become easily taught when faced with the slightest of issues.
Mercutio is one of the Dragons Dee rescued however due to a birth defect he was born a Drake (a wingless dragon). Due to this deformaty Dee knew he wouldn't be of any use to any dragon taxi companies, and decided to keep the hatchling and name him Mercutio. Mercutio became a real source of comfort for Dee. Unlike his friends that have complex and difficut emotions, Mercutio is very peaceful precense. Dee attibutes a lot of his healing to Mercutio.
The Keep is one of Dee's aquantinces whom he knows through Elvin, as Keep is the main person that houses, feeds and clothes him. Dee's friendship with Keep is more of a polite co-parentship then anything else.