Is possible to change the endings as many times as you want as long as you select YES when you get asked to rewind:
After that, don't start the Mother Claudia quest otherwise you need to do this whole process from the start.
Before continuing, you need to complete some requirements:
- ArFa-Sys, Kureha, Zeliska, Itsuki, Bazalt Joe
- 3rd Date
- Level 4 affinity with 75%
- Itsuki should give you a gun (awards the "Gift of a Gun" achievement)
- Kirito, Azuna, Liz, Silica, Sinon, Leafa, Klein, Agil, Premiere, Strea, Rain, Philia
- Crafting Quests: Asuna, Agil, Liz
Once you complete the requirements, go to your house and an event should trigger with your ArFa-Sys. It should give you a charm that is required later.
You can continue the story mode as normal.
Once you log out and log back in with the NerveGear, the quest should be named "Fatal Bullet" rather than "The End of All". Instead of fighting the boss as normal, hit him in the green part of the chest to prevent him from attacking.
If you manage to avoid all of the attacks,
Itsuki is going to reveal itself as the antagonist
and another boss is going to appear. Do the same as the first one.
After you finish the quest, you should get the normal "Quest Complete!" message and a scene where
You and your complete squad bait a group of PKs
Once this scene is completed, you should get the achievement called "A True Hero".