How NOT to Summon a Demon Lord: Volume 8 (Light Novel)

"Instruct me in swordplay, Swordmaster! I'll allow it!"
Having finally become king of the elves, Diablo and Shera spend their first night as king and queen together... After, Diablo and his group return to Faltra. He visits Edelgard, deals with a crime syndicate...and bathes Klem?! After this brief pause in their journey, the group makes their way to the northern mountains located in the Demon Lord's domain. Realizing he might not win the upcoming battle with the Demon Overlord, Diablo decides to rely on the swordmaster to help him level up quickly. Will Diablo manage to master the blade, all for the sake of defeating the Demon Overlord?!