Last round Arthur (Fantasia Bunko) [Light Novel]

[Machine Translation] Rintaro Shinigami is a high school student who spends his days in emptiness because he was born with the ability to do everything too well. To pass the time, he dares to join the camp of Runa Artur, who is called "the weakest", and participates in the "King Arthur Succession Battle" to decide the true King Arthur in order to save the world from the coming crisis. But... My Excalibur... Runa is a scoundrel who sells off the Holy Sword and uses the summoned "knight" Sir Kay by making him dress up as a costume. But in a desperate moment of crisis, Runa shows a glimpse of strength that even Rintaro recognizes. A new legend of King Arthur begins here!

生まれながらにして、すべてのことが出来すぎてしまうせいで空虚な日々を過ごす高校生、真神凛太朗。暇つぶしのため、あえて“最弱”と呼ばれる瑠奈=アルトゥールの陣営に加わり、来るべき世界の危機を救うため真なるアーサー王を決める“アーサー王継承戦”に参加することになるのだが...。「私のエクスカリバー...売って、お金に換えちゃったから」瑠奈は、聖剣を売り払い、召喚した“騎士”のケイ卿にはコスプレさせて利用したりするロクでなしで!?しかし絶望的な危機に瀕した時、瑠奈は凛太朗さえも認める強さを垣間見せ―。新たなるアーサー王伝説がここに始まる!