Reincarnating In Tensura as a Demon

( Rewritten Synopsis ) a bit fast paced novel Ken Luin a Prince In one of the Leftover worlds On his Marriage day is killed by His Fiance and his Father , accidentally reincarnating into the cardinal world of Tensura He Gains power and will develop himself _______________ The concept of a Leftover word : So Basically You all know about how the Tensura Verse was created , a will decides to create a world out of boredom , then the will Abondoned it's plans for constructing a world but it had already created the basis for the world , then Veldanava the oldest true dragon was born and he decided to continue world creation on his own , but in this concept what if that will did create some worlds but Abondoned them and because these Leftover or Abandoned worlds were created by the will not Veldanava so they will have even stronger beings in it stronger than even Veldanava ( Also these worlds weren't in Veldanava's Knowing ) ( Please before Judging Read Atleast 10 Chapters of the book or the number of chapters completed at the time you're reading if even 10 chapters are not completed , You'll love it please give a try )