Disclaimer: I own none of the characters from Sword Art Online, I'm only borrowing them for awhile. Don't sue me, I'm really really broke. This divergence takes into account events up until Mother's Rosario, and ignores Alicization as it hasn't got a North American release.

Sword Art Online III: Asgard

Introduction

Alfheim Online was a unusual, and in some ways dangerously flawed creation.

Created by RECT Progress Inc under the direction of Sugou Nobuyuki, Alfheim Online was supposed to be a MMORPG, in which characters attempted to reach the top of the World Tree to meet the Fairy King Oberon and be transformed into ALFs, with the power of unlimited flight. However that was a lie, and the top of the World Tree was in fact a lab where Sugou experimented on captives taken from Sword Art Online.

(The World Tree stirs. Where once it merely stood, branches swaying slightly in simulated breeze, it begins to grow. Fed by the waters once denied to it in Jotunheimr, it reaches up, straining.)

After Sugou's criminal activities were discovered the game development elements of RECT went out of business, and the ALO servers and game were bought up by a group of ALO players and investors. They successfully restarted the game as well as attempted to 'patch' it to fix the flaws introduced by Sugou, including his lab. They erased the lab and replaced it with Yggdrasil City, as well as introducing other changes.

(The floating castle of Aincrad circles the World Tree. Once part of Sword Art Online, it was restored by Ymir, the company now running ALO. If you stood at the edge of one of Aincrad's floors and looked up at the Tree, you would have seen the glowing lights of Alne at the base of the Tree, and Yggdrasil at the top.)

After Sugou's defeat, the basic game engine of SAO and ALO was released to the internet. With the built in editor and a computer with enough processing power, a creator could build from scratch any virtual world they wanted. Soon hundreds of new game worlds cropped up, all running on the same program. But the system that ran those games was subtly different that that of SAO and ALO.

(Those in Yggdrasil felt something odd, but couldn't quite explain it. Agil paused in bargaining with a customer as he felt the floor shiver slightly, then looked around curiously. In another part of the city Lizbeth finished hammering a new blade, nodding in satisfaction. As she hung it on the wall, she too felt... something off, but couldn't say what it was.)

SAO was governed by a powerful, self monitoring system called Cardinal. That same system was copied over to run ALO, but unlike in SAO it was implemented improperly. Cardinal, in ALO, was now creating new quests on it's own, building NPCs and in one case, very nearly wiped out the game itself. Only the heroic actions of Kirito and others successfully completed a quest and prevented Ragnarok.

(Above Yggdrasil, in the upper branches of the World Tree, a light began to shine. As the branches reached up and enfolded it the light grew brighter, as the Tree formed a sturdy base for what was forming. Out of the light a mighty island descended, as the world looked on in awe.)

The Cardinal system had introduced the latest addition to ALO.

ASGARD was here...

To be continued...

Notes: Trying to explain why a new section of the game could just appear out of nowhere. Concepts from Asgard have already appeared in game during the Calibur story, so it's not unprecedented. Because ALO has not consistently adapted Norse mythology, I too will likely adapt concepts loosely in this story.