Tensei Ōji ga Gensaku Chishiki de Sekai Saikyō

Tamotsu, a hardcore gamer who had been speedrunning through the game "Destiny Slayer", died and was reincarnated into another world... But as Luster, the good-for-nothing villainous imperial prince, of all people?! He's the absolute weakest of all the enemy bosses, and is going to be sentenced to execution in five years! But in order to save his favorite heroine, the animal-eared maid Zina, he'll make full use of the knowledge from all his speedruns, as well as his love of the original game, to become unmatched! Source: Kodansha