Redwall meets Shield Hero Isekai with a Vampire twist. The Vampire Castle of Vrancz is under attack by the Ratmen Rodiens Empire. So its Batty Bat Lady Sorceror, Ynqths Hereid Seraien, decides to do the same thing as she did last time. Summon someone from another world. She summons Satoshi "Ash" Amaiishi, who sold homes. That's not good. The last person she summoned sold himself off to the Rats.