Yuuto and the Steel Clan seek to save the people of Yggdrasil, but they face their greatest obstacle in the form of the Flame Clan’s Nobunaga, the would-be conqueror of the continent. As the two clans come to blows, Linnea holds off an assault from Shiba, the Flame Clan’s greatest warrior, at the Wolf Clan capital of Iárnviðr. Faced with possibly the most powerful enemies it has ever encountered, can the Steel Clan protect its people from the threat of the Flame Clan?! As the destruction of Yggdrasil begins, the greatest battle in its history unfolds... Find out more in this 18th volume!

Some urban legends are best left untested! Yuuto Suoh gets more than he bargained for when he joins his childhood friend Mitsuki Shimoya in testing out an urban legend. When he uses his phone to take a picture of himself with the local shrine’s divine mirror, he is whisked off into another world – one heavily steeped in the lore of the old Norse myths. Using his knowledge gained from school and from his solar-powered smartphone, he has the chance to bring the Wolf Clan, the same people who cared for him, to prominence, all while earning the adoration of a group of magic-wielding warrior maidens known as the Einherjar.

Yuuto and the Steel Clan have little time to celebrate their victory against the Silk Clan as the Flame Clan Army resumes its advance. Once again, Fort Gashina is the center of the conflict. The Horn Clan Army under Rasmus attempts to hold the fort in Yuuto’s absence. Can Yuuto, with his cheats, defeat the legendary Oda Nobunaga, one of history’s greatest strategists, once and for all? The long-awaited Battle of Yggdrasil begins in this 17th volume!

From weakest to strongest: A loser rises to become a sovereign! As the patriarch of the Wolf Clan, Yuuto is now a figure of undeniable power and authority. But the Yuuto who found himself transported to this world of Yggdrasil two years earlier was nothing more than an immature boy. He grew as a person thanks to those around him, such as the warrior maidens Felicia and Ingrid. And in particular, there was a reliable, older brother figure... In a world ruled by strength and the law of the jungle, just how did Yuuto come to be the sovereign ruler of the Wolf Clan? At last, the story will be told: The Master of Ragnarok's "Episode Zero"!

Some urban legends are best left untested! Yuuto Suoh gets more than he bargained for when he joins his childhood friend Mitsuki Shimoya in testing out an urban legend. When he uses his phone to take a picture of himself with the local shrine's divine mirror, he is whisked off into another world -- one heavily steeped in the lore of the old Norse myths. Using his knowledge gained from school and from his solar-powered smartphone, he has the chance to bring the Wolf Clan, the same people who cared for him, to prominence, all while earning the adoration of a group of magic-wielding warrior maidens known as the Einherjar.

Strategy versus power: The showdown with Steinþórr and the Lightning Clan approaches! Yuuto has finally come clean with Linnea about why he can’t marry her. But just as it seems they’ve reached an understanding, troubling new information arrives: The Lightning Clan is preparing to launch an invasion! Steinþórr’s army is fierce, and the man himself possesses monstrous inhuman strength. Yuuto has reliable allies like Sigrún and Skáviðr, and he has his “cheats” — tactics and technology he copied from future history. But will that be enough for the Wolf Clan to prevail against a foe said to be invincible?

The great earthquake continues to wreak havoc upon the battlefields of Yggdrasil. Witnessing the collapse of the Gjallarbrú Fortress, Nobunaga wastes no time ordering a full assault, forcing the Steel Clan to fight a perilous retreating battle. Meanwhile, Sigrún, swept away by the surging waters of the Körmt River, finds herself forced into a deadly duel with Shiba, the mighty general who had defeated her just months earlier. Faced with their greatest threat to date, can Yuuto find a path to survival for the Steel Clan?!

Yuuto's new Nordic life isn't the Hygge-filled heaven he may have hoped for. The Wolf Clan face continued challenges from outside, and a tenuous grasp on control by the benevolent, ageing patriarch within. As past memories resurface, Yuuto finds that conquering the discomforts of his modern upbringing could be the source of salvation for everyone involved - but can he turn that information into iron before the next battle begins?

Poor Yuuto just can't get a break. He's got girls from every clan flinging themselves at him to establish an alliance, when all he wants to do is get back to his one true love at home. Of course, it would be easier if rival clans weren't sending spies and loudmouthed warriors his way as well...

A Clash of Strengths; A Memory of Weakness Yuuto's war with the Lightning Clan comes to a head in a showdown at the river's edge, but it's going to take every trick in his book to survive... can he keep not only his own head, but save those closest to him as well? And how did he end up in this mess to begin with?