Original Dark-Fantasy series concept

I was lingering on this fantastical series for a while. It's a dark fantasy story inspired by the likes of the Devine Comedy, Demon Souls, and other tails of knights and fairy tails.

The story goes; After a great battle, a knight awakens in a grassy plain surrounded by a thick wall of fog. The only object visible is a large canyon (A Grand Canyon like In scale) with an enormous castle that bridged between. The castle is made of glamorous and gothic chiseled stone. The structure pillars (like a conjoined stalactite and stalagmite) through the sky and deep into the seemingly bottomless chasm. It seems to only have one entrance and exit, from one side to the other. 

The knight may try to flee but venturing into the fog only brings him back to the castle. He walks across a massive drawbridge made from an impossibly large trees (maybe Redwood trees) and held by chains made from enough iron to arm a million men in clad (Fucking huge.) Inside the walls is a rotted kingdom. Streets are seemingly bare except for the few brainless, cursed citizens. The only "normal citizens" hide away fearing for their lives. 

I was thinking, the adventure follows the knight venturing through the kingdom and its many layers like the Devine Comedy. The main antagonists are the monarchs and other head leaders of the kingdom, each representing the 7 deadly sins:

• The King of Pride; Is so proud of his kingdom, he doesn't see the corruption that consumes it.
  
• The Queen of Lust; So beautiful, with skin so dark. She towers like the night sky with her eyes that shine like stars. Seemingly good but like a medusa where if you look into her eyes your mind rots.
  
• The Sister of Envy; The royal sister of the King, who is in love with the queen she will do anything to her brother to get her. 
  
• The Duke of Wrath; A second hand of the king who practically runs the kingdom with an iron fist and a bloody whip.
  
• The Speaker of Sloth; A heretic preacher that lives in a womb of his disheveled/crippled mother, too lazy to let himself be birthed after what may be hundreds of years. 
  
• The Parasite of Greed; A worm that lives like a tumor in the skull of the king. Planted by the sister. The worm speaks to the king, telling him to reach higher and dig deeper. (might change it into a person like Grima Wormtongue from LOTR)
  
• The Chief of Gluttony; Easily the largest of the sinful figures. He lies in the core of the kingdom feeding whatever to everything. His food is one of main reason the kingdom still lives on. He also guards the child of the King and Queen, as if it were his own. 
  

At some point the knight slays each figure one by one. Ending with him destroying the kingdom and escaping with the child and other citizens. Then after that he builds a more wholesome kingdom, blah, blah, blah, bittersweet/ambiguous ending. 

If this sounds cool or absolutely horrendous, tell me. 

Questions are also welcomed. (Sorry for any grammar mistakes I've made.)