Tower Dungeon manga volume 1 features story and art by Tsutomu Nihei, the creator of Blame!

An evil sorceror slays the king and takes over his body, kidnapping the princess and spiriting her away to the legendary Dragon Tower.

The Royal Guard is rebuffed in their attempt to rescue her, and to replace the wounded, a young farmhand named Yuva is called up into service. With only a potlid for a shield and a strong back to carry supplies, Yuva joins the soldiers on the perilous quest to climb the tower and rescue the princess. But the Dragon Tower houses untold horrors…!