Situated deep within the 15th Hierarchical City of Torifune, the Guardian protected the Conversion Grimoire from those who would seek it by venturing to his desert level. He would often take the form of a ant lion pit which had been mutated by seithr - many people fell into it and died, abandoning their comrades and loved ones, leading the Guardian to start losing his faith in people.
Having created a mirage to entice more people to his location, the Guardian watched as Makoto Nanaya fell into the ant lion pit. Mai Natsume fished her out of the quicksand, burning her chest by doing so. Overjoyed, the Guardian showed his true form, congratulating them on their bonds. He then offered Team Remix Heart a choice - take the Conversion Grimoire, or the Azure Grimoire. Mai chose the former, telling him that she was going to obtain what she came for. Impressed that she had passed his final test, he gave her the Grimoire and revealed that the Azure Grimoire was merely a fake. 
In the desert still, the Guardian was enjoying his own company before he was found by Relius, who addressed him by his true name. Ignis placed her claws over his mouth, and he disappeared from Cypher Albar's sensors. 
- BlazBlue: Remix Heart, Chapter 06
- BlazBlue: Remix Heart, Chapter 17