Kyuuketsu Hime wa Barairo no Yume wo Miru

An unexpected accident put him into an eternal sleep, but when he wakes up, he finds himself transported to the world of the game he was playing! Reincarnated as the game's main character, a beautiful vampire princess, "he" is the ruler of a huge demon empire, surrounded by the followers he had raised in the game...! (Source: Garden Comics, translated))