The Ultimate Sorcerer

Merlin disgusted with the world decides its time for a change. He and four other powerful Sorcerers along with dragons create a kingdom in the sea.
1000 years later Oliver a budding sorcerer is coming into his powers. He must traverse the deadly line between doing what's right and what's expected. 
The young sorcerer Oliver is put through trials to ascertain his true strength.  He has more power than he knows and either everyone wants to kill him or be him. Oliver starts a battle against societal norms of owning slaves and fighting against the status quo without messing up relationships. His biggest obstacle is finding out who is the puppet master and who are the puppets.
This novel delves deep into slavery terms and what happened in the middle ages. This novel centers on submission, and heavy domination. This includes punishments, sadism, and masochism. Every character that deals in this sphere is over 18 years of age. This has slavery themes and has both women and men put into submission by choice and reluctantly.