While Meliodas was being treated by Dana, Friesia finds the group through one of his insects and decides to launch the first offensive. Diane engages Friesia in combat to protect her captain.
Friesia controls a huge swarm of insects and has them spray highly destructive and corrosive poison to kill the Deadly Sins along with the rest of Dalmary Town. Though being afraid of insects, Diane, overcomes her fears for helping her captain and raises several pillars from the ground to crush them.
After killing all of them, she dashes towards the Baste Dungeon to search and defeat Friesia as the Holy Knight excitingly readies her whip for battle. On her day, Ruin intervenes into the battle, hypnotizing Diane and, later, Meliodas into fighting each other by making them believe that the other was the Holy Knight. After Elizabeth finally breaks the illusions, releasing Diane, and Ruin is defeated by Meliodas, Friesia is utterly defeated by the Sin of Envy with a single punch.
After defeating Ruin and Friesia, Meliodas and Diane enter the Baste Dungeon and encounter Cenette who is fleeing from Ban due to him having just killed Jude, and screaming for help. Ban then appears behind her, with him and Meliodas' greeting each other with high fives and beginning to arm wrestle, which destroys the whole dungeon.