Demonic Host Against The Bloodline

Feed on the different vampire blood groups to swap powers. 

Warning: Do not drink human blood, strength level will fluctuate.

[Powerful blood group: O negative | Chaos elrment | nearly extinct]

••• 

Zaiden Rivers is determined to restore the health of his father who has some strange disease. While his mother is missing, Zaiden's actual lineage is unknown.

At the age of thirteen he's already a criminal genius. Rumored to be responsible for the killing spree, his targets are vampires. The possible cure around is the heirloom of some royal vampire family. 

The tables turn when he's killed along with his butler. And both are summoned as Demon host and Ghost partner, along with a guiding system. 

Will he be able to live up to the progenitor's blessing? Or the so-called cure isn't just the sole stimulus of his madness! .
干呕看帅哥了解自己
[Not heavily system novel, rather a tech-magic blend.]