Even Given the Worthless ""Appraiser"" Class, I'm Actually the Strongest 16

Yuri has gone to Theresia's World Tree to save Ein, only to find that Ein has become Theresia's guardian and lost all of his memories. Meanwhile, the other sisters are holding back the demon army's attack, but when Riddler becomes a demon god, all hope seems to be lost. With the kingdom on the verge of annihilation, a shining ray of light appears! And the battle reaches its climax as the true dark mastermind arrives on the scene…