Bine and his strange power

[idermailer]

I saw all endings of this game, but I couldn't found why bine can use Brave arts.

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How we know that Bine have Jin tribe's power:

1. Lunaria feels some strange taste from Bine, and it is same with Alma's. Alma is Jin Tribe's member.
2. Bine removed false companions, and Orio says Bine Used Jin Tribe's power.

But HOW and WHY? I don't think a man can get power of 'do anything' from just trusting others. Moreover, he said His parents are Fai tribe's member both, undoubtedly.

Is there any reason I didn't noticed? Or we can NEVER know how?