Maseki Gurume: Mamono no Chikara wo Tabeta Ore wa Saikyou!

A reincarnated boy with a secret skill aims to become the great king! Ein reincarnated as a noble with the skill "Toxin Decomposition EX". The skill was not something he wanted, so he was disappointed... but then learns that he has a very rare talent to absorb magic power by eating magic stones. They even taste good! He then found out that his real identity was a prince of the largest kingdom of the continent. He was luckier than he thought! (Source: BookWalker Global)