The journey of dragon transformation starting from Demon Slayer

Tazmi frowned when she found herself underground as soon as she traveled through time. Looking at the jagged rocks and the huge dark space around him, the young man clenched his fists. As time slowly began to flow, the boy who had not fully adapted to the environment soon encountered the first wave of enemies. How could something like this appear underground? Is this... a monster? still? The young man who narrowed his eyes looked at the monsters surrounding him and slowly raised his arms, gripping the evil spirit in the scabbard behind his back. [Note: The content includes the heroine being reborn with memories. The settings added by the author may seem a bit awkward. Readers who cannot understand can understand it as a simulator...