Blade & Bastard, Vol. 2 (manga)

After losing his friends and being banished from his clan, the bandit Raraja takes on a mission from a mysterious man in a bar, only to find himself trapped deep in the dungeon with Iarumas and Garbage. What's worse, awaiting the impromptu party is a huge gas dragon and a swarm of dragonflies! But as Raraja cowers before the terrifying foe, Iarumas delivers upon it a lightning strike bearing the name of a god...!