Thank you for the replies. I had never heard of this "Cult of the Dragon" until now but found an article on the Forgotten realms wiki.
Regarding religion I read the following:
"While some dragons were worshiped as deities by their devout Cult servants, which the dragons certainly enjoyed these dragons received no divine powers and could grant no spells to their followers.[1][4] Nevertheless, dracoliches were considered as almost divine and were titled 'Sacred Ones' within the faith.
Otherwise, the Cult of the Dragon had no official patron deity. The few clerics in the Cult venerated Bane, Shar, Talona, Talos, and Velsharoon, and to a lesser extent Cyric, Gargauth, Malar, and Tiamat. The necromancer mages mostly took Velsharoon as their patron, to avoid paying even lip service to Mystra, because of her church's opposition to the Cult of the Dragon."
It sounds like I can be a member of this cult and easily get away with serving Velsharoon or Cyric, or just worship the abyssal powers in pantheon.
Thank you for the guidance. The character is slowly coming together with your help.