Magician Who Rose From Failure (Manga) Volume 3

Arcus is still leveraging his otherworldly scientific knowledge to improve his magic. On hearing news that Lecia, his beloved sister, had been kidnapped, Arcus set off to rescue her, only to be thrown into the Holy Tower. There, he runs into an old friend...or rather, enemy. They say no one can escape the Tower, but if he doesn't, there's no telling what might happen to Lecia...